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Eco-Marathon Team Hits 2,843 mpg
At this year's Shell Eco-marathon Americas event the team from Mater Dei High School shattered last year's record by traveling 2,843.4 miles on a single gallon of gasoline. "How did the Evansville, Ind., team come up with its winning airfoil-meets-teardrop design and beat out its largely collegiate competitors? "It comes from trial and error, seeing what works and what doesn't," an unidentified student and team member told a local newscaster Friday. Those top three vehicles, like most in the competition (25 out of 33 total), used internal combustion engines. The goal for all entrants was to travel as far as possible using as little fuel as possible. Vehicles--sans driver--couldn't weigh more than 160 kilograms (352 pounds), while drivers had to weigh at least 50 kilograms."
Its Shell sponsoring it, of course non-gasoline vehicles weren't eligible for the grand prize...
Damn corporate scams for cheap publicity and easy recruitment.
And adjusted their carburetor. Now it only gets 30 Miles per gallon.
What It could happen...
Ask not what you can do for your country. Ask what your country did to you
It's not supposed to be for production, numb-nuts. Forumla 1 racers don't have AM radios, either, nor power windows. They must suck, eh?
Anyhow, I was wondering why there is an upper limit on weight in this contest? It seems like it's harder to get good mileage in a heavier car, so what gives with that?
Currently hooked on AMP
My 1963 car gets 40mpg. Sure it's an 2-cylinder NSU Sport Prinz but even the 1960s Darts I've had got 25-30mpg with a slant six.
I don't understand why modern cars get such lousy mileage.
riding round the world on an old motorcycle
Let us briefly pause whilst my 1988 Mercury Grand Marquis sputters loudly with contempt.
Hideously over-sized engines would be my guess.
I don't understand why modern cars get such lousy mileage.
Air conditioning, for one thing.
If I have been able to see further than others, it is because I bought a pair of binoculars.
Schwab
Editor, A1-AAA AmeriCaptions
What's the conversion so that solar cars can get "MPG" of gasoline?
I wonder if there's some trade-off between fuel efficiency and lower emissions that explains this.
-l
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Anti-pollution devices. You can thank 1973 for that... :)
it's easier to claim thousands of miles per gallon on such small vehicles than it is for a typical car. "we got 3,000 miles per gallon!" sounds far more impressive than "we got 100 miles per gallon" even though 100 mpg is amazing in of its self they are looking for overkill.
Sigs are too short to say anything truly profound so read the above post instead.
The implication is that the achievement is not a matter of fuel/applied power efficiency alone. If the primary reason (most of these) contests exist is relegated to an afterthought, the arbitrary rules that allow for such a minimal design seem silly. Why isn't the car tested in a lab if you're going to remove it from the realm of real application anyways? What's the point if not a theoretical application of minimalism in a controlled environment? If you want a fuel efficiency competition you probably don't want it to be influenced by the rule of thumb that the mass of the car can be shrunk. When you get a 4-runner to go 1000 miles on a gallon of gas, I'll take notice. Till then, these competitions are relatively pointless imo.
Often wrong but never in doubt.
I am Jack9.
Everyone knows me.
I've heard this accusation before, but I don't grok it at all. My limited understanding was that anti-pollution devices were supposed to squelch unburned hydrocarbons emitted by inefficient engines. However, if your engine is more efficient -- if it more completely burns hydrocarbons -- then the emissions controls should be superfluous.
Could you explain this to me? In concrete terms, how are contemporary emissions controls impeding the development and release of more efficient vehicles?
Schwab
Editor, A1-AAA AmeriCaptions
It's sarcasm. No shit it's not for production. Like they're really going to make a car that gets 2k mpg for mass consumption. go back under your rock.
Just imagine walking out to your car in the morning, getting in, turning the key, and kaboom!
According to this video that's almost 10 times farther than a person could walk on a gallon of gasoline... if a person could metabolize gasoline, of course.
- Greg
Start a happiness pandemic
Modern cars get better mileage with the windows rolled up and the AC on than with the with the AC off and the windows rolled down. Of course the best mileage is with the AC off and the windows up, but the passengers might be done to medium-well at the end of the trip.
Some mornings it's hardly worth chewing through the restraints to get out of bed.
Weight.
Crash test standards add weight. Power windows, power-adjustable seating, 6-disc in-dash CD changers, power moonroof, they all add weight.
Colin Chapman, the founder of Lotus, pointed out that "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere." He was going for speed, but the same thing applies to fuel economy.
Consider a car that's a lot newer than those you mention: the 1985 Honda CRX. It had a 76-horsepower engine, and it had a 9.1-second 0-60, and 32 miles to the gallon. It was able to do that because it only weighed 1860 pounds.
1860's unthinkably light by current standards. I drive a Mustang GT that has a curb weight of something like 3860 pounds, so that's more than two tons with a driver and a tank of gas. You want a performance car that's even close to that 1860lbs, you end up with...a Lotus Exige, which is about 2000 lbs. And costs a hell of a lot more than an '85 CRX.
Yeah, your guess sucks. Advances in engine technology have been utterly remarkable over the past several decades, to the point where Honda can squeeze well over 200 horsepower out of a naturally-aspirated 2-liter 4-cylinder engine. Specific power has increased by incredible amounts since the cars the poster was referring to.
Cars have gained ridiculous amounts of weight since the 1960s, but that's not because of the engines.
Also, an essential strategy for achieving high mileage is to burn the engine at optimum efficiency RPMs to quickly get to speed, and then use your mass combined with low aerodynamic and rolling losses to coast as long as possible (frequently almost to the point of stopping). This is why there are required average lap speeds and maximum speeds. Of course, this strategy could hardly be used in production vehicles or in public roads.
a 2.0L engine in 1966 produced 90 hp whereas a new 2.0L engine will generate upwards of 200hp... the extra engine efficiency has gone towards more power, because thats what consumers want
Second, modern cars have bigger engines. Even a tiny town car in Europe often now has a 100BHP engine when 20 years ago it would have been 60. More acceleration, more wasted power, plus the bigger engine just takes more power to turn over. Third, modern fuel has a lower octane rating than older fuel, and so must use a lower compression ratio - which means lower efficiency, as you find out in basic thermodynamics. Finally, air con,power steering, all need power to operate. Even the most basic model of possibly the most basic car in Europe - the Hyundia i10- has air con, power steering, and a 60HP plus engine.
Despite this, the best modern engines are remarkably good because of advances in fuel injection (both Diesel and gas), and because the timing cycles and better valve gear result in less port wastage. The real fuel consumption of that 2007 Diesel is about 80% of my 1990 non-turbo mechanically injected model of the same weight and size, which is pretty good.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
If you read the article, the top competitor using gasline got 163.5 MPG. It does say they used Internal Combustion Engines, and it doesn't say what they did use but it's not gasoline. It doesn't say whether that 2843 MPG is miles per gallon of some other fuel of if they gave them the engergy equivalent of 1 gas of gasoline in that "some other fuel" and measured how far they went on that. Or maybe it's something else completely. The article is poor on details.
Real programmers use "copy con program.exe"
How can you possibly ``cheat'' with a heavier vehicle?
Real cars weigh a lot more anyway.
If someone happens to find a way to win with a 300 kg vehicle, what's wrong with that?
Modern cars get better mileage with the windows rolled up and the AC on than with the with the AC off and the windows rolled down
... the AC's draw is less efficient anytime your speed is not high enough to create a lot of drag from the windows down.
You need to caveat that with 'at highway speeds'
i don't really get that. a window air conditioner draws less than 1500W (about the maximum you want to pull from a 15A household circuit, leaving a safety margin). that's just less than 2HP. the system needed in a car could be significantly smaller, given the smaller volume of air that needs cooling (OTOH, some of the newer SUVs might have a larger air volume than some apartments), so it would seem fairly small compared to the load of the rest of the car, unless my thinking for the car load is off by a lot.
upon the advice of my lawyer, i have no sig at this time
I don't understand why modern cars get such lousy mileage
Hmm? My '06 Pontiac Gran Prix GT with the supercharged V6 @260 horsepower has gotten an even 25 mpg over 24k miles...mostly freeway miles, granted, but still WAY better than 260 HP vehicles from the 60-70's.
That depends on your speed. Yes, I'm pulling out MythBusters because not only did they do this experiment, they went back and repeated it because they inadvertently screwed it up the first time.
The cut off point for when to use A/C or not is 50 mph. Below that, it is more efficient to leave the windows down than it is to use the A/C. Above that speed, the reverse is true.
How did they screw this up? They went 50 mph and tried things both ways. D'oh!
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
You're saying two contradictory things. Modern cars only get better mileage w/ the windows up assuming they're going fast enough for the aerodynamics to make a difference.
Your 1963 car also has 30 horsepower. Modern cars put out 80+ hp while giving similar figures (e.g. Ford Fiesta). (Diesels are even better, but they're not necessarily any more cost-effective due to price fluctuations)
I make websites and stuff. Buy one.
Well, to start with, the anti-pollution devices don't make the engine more efficient. They eliminate unburned hydrocarbons and nitrous oxides. Sometimes these anti-pollution systems actually use available horsepower to do their jobs. In some cases they reduce the efficiency of the engine, in order to reduce emissions.
One good example is the catalytic converter. It is in the exhaust stream, post combustion (usually mounted under the floor of the car). It works by catalytically combining oxygen, often pumped in, with any unburned hydrocarbon (CO, for example). Having the catalytic converter in the exhaust system acts as a restriction. So, it requires power to pump the oxygen it needs to do it's job, and it reduces the engines efficiency by increasing back-pressure.
I think you get the idea. I've read that the pollution control hardware costs the typical vehicle a couple of miles-per-gallon in efficiency
As to no longer needing them, once you improve the efficiency... Well, now that the laws are in place requiring the emission control systems to be included, it's always harder to undo a law, so there will be very little effort in that reguard. No politician wants to be known as the one who submitted the bill to remove the emission control devices. Particularly in today's political climate. In fact, the trend is to go the other way: If the engine becomes more efficient then the emission control system should be able to remove even more unburned hydrocarbons and nitrous oxides; and, the requirements therefore become stricter.
How about a contest where the results can actually benefit a normal car?
http://www.progressiveautoxprize.org/
First of all, the US polution requirements rules out the use of diesel engines in cars. While the majority of European cars are now diesel, the only way to get one in the US is to buy a huge honking truck.
For petrol engines, the emissions requirements need a lower temperature burn, which is inefficient. Inefficient, means more petrol.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
I have a 460hp (modded) car that got 38mpg on a LA-San Diego round trip. At the same time, it gets about 2mpg at full throttle and top speed. There is nothing wrong with modern engines, but if you have a ton of power and habitually use it, you will pay in fuel.
And do not forget, modern cars are heavier because of safety requirements, noise reduction materials, power everything, air conditioners, etc...
No good deed goes unpunished...
Modern cars have to meet vastly-increased safety standards, which require more material. People will not tolerate a 1700-pound car like the Honda CRX (which in its day got 70mpg in the HE edition) because cars of that weight crumple like beer cans. There are also increased demands for road holding (wider tires, which weigh more and have more rolling resistance), ABS brakes (added weight), more leg room (longer body = more weight) and more head room (higher body = more weight and increased frontal area, hence increased drag).
There is also a demand for increased performance. Even in fuel-economy-oriented cars, 0-60 of much more than 8 or 9 seconds is not considered acceptable. And if a car company can't make money selling a car (which requires a certain number of units to meet economy-of-scale), they are not going to make it. Car companies are not charities.
If someone were to resurrect the Honda CRX HE with its 70mpg, nobody would buy it.
Everybody gets what the majority deserves.
from the Shell website
rules
I haven't read all of the rules, but it appears they only go 15 mph.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
My Dad's old Corrolla would get 44mpg. He used to track it in his little notebook every time he filled up. It was carburated, 4-cylinder, seated 4, and ran over 200K miles before he sold it. How the hell do today's manufacturers get away with boasting/advertising 25mpg?
you've probably noticed already, but these are not practical vehicles. We're talking about single-person, prone-position, ground-hugging, 10-20 MPH vehicles. Of course you can get 2000+ MPG with those conditions! The Progressive Automotive X Prize is about practical vehicles getting 100 MPG (or equivalent). Now that's a race whose outcome is interesting! Check out some of the X Prize Cars which have already been designed.
augment your senses: http://sensebridge.net/
You're right, the weight that cars have gained has not been because of the engines, but the other poster never said that it was. He said that engine sizes have increased, and he's right. The additional weight has resulted in a significant increase in the sizes of the engines to compensate for the added weight while maintaining or increasing performance. So yes, the increased fuel consumption is because of bigger engines. The bigger engines, in turn, are because of the increased weight.
So I wouldn't say his guess sucks. It sounds like it was right on, he just neglected to boil it down to the root cause. You're both right.
Random and weird software I've written.
Actually you are incorrect. Diesel cars are allowed in the US: http://www.caranddriver.com/reviews/hot_lists/car_shopping/2008_new_car_reviews/2008_volkswagen_jetta_tdi_first_drive_review And VW has had several of their cars using Diesel here in the US for a while.
unimatrixzer0
There are many ways to be more efficient - more complete combustion is only one. Better heat transfer, less wind resistance, less weight, etc. all make a more "efficient" vehicle without necessarily more complete combustion. This is why a Hummer may pass a emissions test getting 10 mpg while an old Civic fails getting 30 mpg. The Hummer removes all the unburnt hydrocarbons and passes while the old Civic releases them into the air and fails - even if the Hummer actually produced more. They are not testing efficiency, only how well the vehicle handles its emissions (and only a few - if they measured CO2 output then the Civic would perform much better than the Hummer). The necessary components required to scrub the exhaust adds weight and reduces power output (as does a muffler - but I think those are here to stay).
Is it just weight? They used to have fuel economy races with normal cars/motorcycles. Sure people would cheat but it'd be cheating with a normal vehicle. I guess that's because watching a slow race for economy isn't as fun and exciting as a race built for speed. These events would be more impressive with say any car made within the last 5 years.
Cars weigh more but now we have fuel injection over carbs and much closer tolerances in engines. Among other things.
riding round the world on an old motorcycle
Not really. The EPA tightened the restrictions on diesel emissions last year (2007). The Diesel technology to meet those requirements already existed, but the excessive amount of sulfer in US Diesel prevented those systems from being introduced here.
Also taking place in 2007 was the change over from Low Sulfur Diesel (LSD) to Ultra Low Sulfur Diesel (ULSD). Because of the time line of the USLD conversion you could still buy LSD up until October/November of 2007, and In theory, the tanks could have a LSD/ULSD mix there after if there was still some amount of LSD in the storage tanks when the first ULSD delivery came in.
So basically, due to really crappy timing on the EPA's part (that ironically enough helped the US manufacturers who had no light duty diesel options), there was only 1 light duty diesel that could be sold in the US through 2007.
But now it's 2008. ULSD is the only Diesel now. VW, Mercedes, Jeep, hell even Honda all have new light duty diesels either already out, or coming out in the US this year.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
From the 2007 leader board:
http://www.shell.com/home/content/uk-en/society_environment/eco_marathon/results/2007_eco_marathon_leader_board.html
The reporter got it wrong (as usual). The single entry was actually running Liquefied Petroleum Gas (LPG) not as he reports "liquid petroleum gasoline". I believe the "combustion" class of which the winner was a part is plain old gasoline, just as the headline states.
I've wondered the same thing. I had a 92 Honda Civic 4 door 5 speed. I could get > 40MPG freeway and approach 40MPG city if I kept my foot out of it. A new 4 door civic is rated at 26 city, 34 hwy?!?
My current vehicle - a 93 Accord gets 28-30 around town.
In fact, the best rated compact gets only 35MPG:
http://www.cars.com/go/advice/Story.jsp?section=fuel&subject=fuelList&story=mpgClass&aff=national
Now that's the EPA estimate - I have no idea how it relates to my actual measured mileage.
It seems every bit of efficiency they squeeze out of the drivetrain, the take away with added weight or performance.
Not sure if the rule have changed or what, but my university (University of Saskatchewan) got 5691 mpg in the Shell Fuelathon back in 1986, and 3086 mpg at the SAE Michigan Super Mileage Competition the same year.
The vehicle weighed 84 lbs and used a 70cc engine.
http://engrwww.usask.ca/affiliation/societies/sae/history.html
In the diesel world fuel is required to burn off trapped hydrocarbons.
On all new 2007+ truck engines a Diesel Particulate Filter is required to trap diesel 'soot'. What happens when this filter gets full is fuel is injected to heat up the the element and burn off the soot.
Also if you run your engine TOO efficiently you create NOx (Oxides of Nitrogen), which is also regulated as an emission. So if you're at a low load condition (say idle) you could get away with burning 0.1 gal/hr. But you'd be spewing NOx, so instead you burn 0.2 gal/hr so that you have 0 NOx (but higher CO2, which is unregulated).
I don't know how it works for gasoline engines.
(Disclaimer, I work for one of the 'big 3' American diesel engine makers)
The team profile on the Shell.com site itself is pretty damn lacking in details. It's a 3 wheeled vehicle in the "combustion" class.
http://www.shell.com/static/us-en/downloads/ecomarathon/2008/mater_dei_6th_gen_final.pdf
Coding with assembly is like playing with Legos. Coding an application in assembly is like building a car with Legos.
Why waste time building it?
Because we LEARN. How many great scientific/engineering breakthroughs were preceeded by someone saying "don't waste your time on that"?
"Strange how much human accomplishment and progress comes from contemplation of the irrelevant."
- Scott Kim
Can we get a "-1 Wrong" moderation option?
Coasting vehicles benefit from high weight (you can coast for longer). However they aren't very applicable to the real world. Therefore the limit is an effort to have the contest reflect reality to some degree.
On the light weight side, I believe the limits are to keep vehicles from costing too much, and to encourage average sized drivers, not just midgets.
The catalytic converter, which is an important part of the emissions control systems in a car, sits in between the engine and the tailpipe. It contains a honeycomb structure coated in a catalyst. For it to work at any real effectiveness, the honeycomb must have many densely-packed chambers the exhaust gasses are forced through.
The catalytic converter is therefore an impedance to the flow of exhaust gasses. In a four-stroke engine the exhaust gasses are pushed out by an up-sweep of the piston. If you restrict the exhaust, the piston "feels" the resistance. Imagine plugging the tailpipe entirely - the result isn't what you'd call "efficient."
There are also a few other complexities introduced with catalytic converters, like the fact that it's much harder to burn fuel lean.
I would have liked this event to use real world type cars. Like a four passenger car. A car that gets 200 MPG and can carry people while doing it would go a lot further then a small one passenger car and that passenger has to be 110 lbs or less.
>Only over 50 MPH.
Good point. I forgot to mention the speed issue. I think it varies a bit over/under 50 depending a bit on the drag coefficient of the particular body. I drive a 1997 BMW Z3. I have a 4 hour drive I take once or twice a month at speeds considerably over 50. With the AC off, I get 30 mpg with the hardtop, 29 with the ragtop up, and 27 with the ragtop down. AC doesn't seem to make a noticeable difference in any of those. The mileage is good, but it does want 91 octane, which is getting a bit pricey.
Some mornings it's hardly worth chewing through the restraints to get out of bed.
At my alma mater, engineering students in the Society of Automotive Engineers club of University of Saskatchewan, entered these contests back in the 80's before budget cutbacks. The year I graduated from high school, 1986, they had a record breaking gasoline powered car that went 5,691 miles per gallon. I think they, or someone else, went over 7000 miles per gallon a few years later. Even in those days 2000-3000 miles per gallon was being achieved by many teams. University of British Columbia achieved 3,145 miles per gallon in 2006.
All the same, I'd like to see the test done with the consumption of an entire gallon of fuel, especially record-breakers. Over a 1000+ mile journey, a lot can happen to decrease fuel efficiency, such as engine contamination, varying atmospheric conditions, etc. Of course, these cars are so tiring to drive, with the driver lying down horizontally and peering around the toes, the fatigue factor will demolish any extrapolated record.
Know your pads. One time pad: good for cryptography. Two timing pad: where to take your mistress.
I'm not sure how this comment ended up as a reply to its parent. It was meant to be in response to the grand-parent, which was the tail of the thread when I was writing it.
You might remember it wrong. While I notced some the users claim that you had an old gutless light-weight car (145hp/2500+lbs) I drove a old slant 6 dart a few years ago, and while I didn't log the gas mileage, it was worse than my V6 Daytona.
Funny you should mention that. I was looking up car weights today, and as I also drive a Mustang GT (a 2007), I looked it up at edmunds.com and it says the curb weight 3356 lb. Also, I believe that curb weight includes the weight of a fuel tank of gas. I also looked up the Exige. It and the Elise used to weigh more like 1800 lb. but have been putting on weight pretty much every year. Anyway, I just thought it was weird you quoted the two cars I looked up earlier today. To add to the Chapman quotes -- "Simplify, then add lightness."
What year is your Mustang?
--sabre86
these cars have "some" gas engine in it. but the winner had over 200 sqft of solar panels and could as well have just used the RV plane gasoline engine in it to provide as a fresh air fan for the driver.
please remember that there are yearly races through australia where cars driver 3000 miles on NO GASOLINE AT ALL.
the REAL winners in this article are the two models that did 300+ and 160+ mpg (on DIESEL) without any solar panels.
now THAT should have been the headline.
Modern day catalytic converters have such a low flow impedance as to practically be straight-through pipes. Auto companies have been working for decades to make this the case as the original (read 20+ year s ago) cats & smog pumps were so terribly restrictive.
This comes up all the time, but it's really not an issue. Your catalytic converter is both not "robbing" you of any power nor is it "decreasing" your gas mileage.
The copper bosses killed you, Joe. 'I never died', said he.
Actually, I found a picture of the car here
It looks like a full-featured car, although there are unresolved ethical problems with such a model.
DATABASE WOW WOW
...12,665 MPG, achived by a Swiss Eco-marathon competitor in 2005. ( http://en.wikipedia.org/wiki/Eco-Marathon )
Gotta love this quote...
Shell points out that "it would be possible for the winning Shell Eco-Marathon UK car to travel three times around the equator on the same amount of fuel that Concorde needed to reach the end of the runway.
That that is is that that that that is not is not.
From the article, drivers had to weight 110lbs or more, not less.
"The past was erased, the erasure was forgotten, the lie became truth." ~1984 George Orwell
Reading several sources it looks like it takes about 30-40 hp to cruise in modern car. That figure is v^2 dependent though and the different aerodynamic figures and different speeds are what causes the figure to be so different.
Sources:
http://ergosphere.blogspot.com/2005/05/getting-down-to-earth_24.html
http://www.oramagazine.com/archive/2004/june2004/TECHNICAL/TECH05/JUNE04_TECH05_01.asp
http://www.geocities.com/MotorCity/Shop/3589/efficiency.html
They ARE out to get you simply because They are in it for themselves and they don't care about you.
Well, I can't point you to a vehicle a tenth as efficient, but this car due out later this year comes in two models -- the Aptera Typ-1h, which gets 130mpg plus has a 40 mile all-electric range, and the Typ-1e all-electric with a 120 mile range. Since power plants have a higher thermodynamic efficiency from burning fuel than gas engines, while battery, charger, and transmission losses are very small, you're looking at almost 200mpg equivalent for the Typ-1e and for the first 40 miles of the Typ-1h's range. So, you're looking at roughly a 20th as efficient, give or take in either direction. The price is a bit steep for a two seater ($30k for the Typ-1h and $27k for the Typ-1e), but when you're nearly or completely eliminating a couple thousand dollars in money spent on gasoline per year for a hundred dollars spent on electricity, and cutting maintenance (the electric drivetrain only has the following moving parts: three wheels, one drive belt, one sealed brushless electric motor; not even a transmission), you can hit payback pretty quickly, and certainly pay off the difference over a normal car in several years. Not to mention, it's all sorts of crazy neat features like in-seatbelt airbags (like small planes use -- they don't explode toward you, but upwards to be between you and the dash, shielding your whole body), StreetDeck (a nifty nav/entertainment system), camera situational awareness displays, and so on.
They're currently moving into their production facility, and plan to offer test drives and factory tours in 30 to 60 days.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
Not to mention that the air conditioning becomes more efficient when there is greater airflow over the condenser (at vehicle speeds at least).
lol: You see no door there!
Thanks for the results list...but the article doesn't say anything at all about the tech behind the cars. Bah.
Obligatory blog plug: http://www.caseybanner.ca/
It depends on a lot more then vehicle speed. Inaccurate blanket statements are an issue with mythbusters. Their conclusion is obviously constrained by several parameters including, but not limited to, wind spd, wind dir, vehicle geometry, AC size, AC COPR, AC control, temp, humidity, etc. Many of these may very well change the conclusion by less than 10%, while others have a serious influence. In any event, five 5 percents add up. That's my problem with mythbusters, they take the most laborious(boring) yet critical component out of experimentation: defining the problem & methodology. This is a good example because the conclusion is essentially worthless. Rather then celebrate science, they completely miss the point.
You might want to spend some more time under a car, or at least read the wikipedia page on catalytic converters or automotive lamda sensors.
... you're on the freeway, you're still getting better mileage. In the future if you're trying to convince people of negative effects of emissions systems, you may want to focus on added weight... or added expense, since the precious metals in the cat that are the catalyzing agents have to add a good $200+ to the cost of the car.
1. The resultant back-pressure from a cat is not significantly larger than that from a stock muffler. If you have a high throughput cat-back exhaust system, you can get a high-flow cat anyway. You might want to think about that, though, 'cuz it's going to be really expensive, and your power and torque gains are going to be in the mid to low single digit percentages unless you've got a whole lot more going on in your engine, despite what fancy "tuner" car people will tell you to justify ludicrous expenditures.
2. Is there really a car made since like 1970 that uses air injection to the cat? Certainly not one with electronic fuel injection... I have a thing for old German cars, granted, so I may have biased experience, but I have *never* actually seen one. It is my understanding that certainly in a modern engine, you'll never see one. Even if there is one somewhere, the alternator resistance to drive a small electric air pump would be what... a tenth of a horse?
Bottom line, unless you're driving incredibly short distances frequently, the emissions system pays for itself in mileage. Your injection system is, indeed, wasting fuel until it's at operating temperature. After that, part of a modern emission system is keeping mileage down and storing oxygen from the exhaust stream after a rich fuel/air mix from acceleration.
Thus: in city driving, there will be no loss at all. If you're on the freeway (and not passing anyone) for a really long time, the EFI may waste a little fuel just to keep oxygen in the cat, but
Mod -1: Unproductive Complaining
More powerful engines do not necessarily mean less gas efficient engines. You might need to use more gas/sec when accelerating off the stop light, but you'll also be accelerating for fewer seconds. Two cars cruising at the same speed, mass, and drag coefficient will need exactly the same power to maintain speed, which is where modern variable valve timing systems can win out (thanks, Honda!)
Since the 1960s, cars have had to add a lot of weight for safety systems, do away with leaded additives, and start using catalytic converters. These have all substantially reduced engine power. That's why muscle cars of the '60s easily had 500hp, while the poor DeLorean of the early '80s was considered a sports car at only 130hp (and that actually was comparable to other sports cars of the time).
There were good reasons for doing all the things above, but we need to keep them in mind when comparing old cars to new ones.
Not a typewriter
"I don't understand why modern cars get such lousy mileage."
Looking at first order causes... cars get poor mileage because energy is lost in:
1) Having to brake.
2) Having to move air around, which eventually ends up as heat.
3) Deforming tyres.
1) is as much a problem of infrastructure design (frequent stops that can't be anticipated) as it is a problem of lack of driver training (for stops that can be anticipated) and obese vehicles.
2) is a problem of convenience and marketability. (Try implementing stylistic obsolescence when every year the shape must stay the same - a modified teardrop.) It is also a problem of overly high speed limits (legislation).
3) is not really much of a problem in comparison with 1 & 2. Can be solved by pumping up tyres and dealing with the bumpier ride.
Of course, all 3 come at the problem from an engineering perspective. If you look at the problem from an oil company perspective and ask the question "How can I ensure that my mode of transport is more convenient (by far) than all alternate forms of transport, that I get another entity (taxation) to fund the infrastructure, and that I partner/own the automobile companies such that they also extract the maximum dollars/year from consumers", you are asking the right question.
It's then a matter of engineering the situation such that no other forms of transport can compete with gasoline/diesel's high energy density and also relatively low cost/volume. And sitting back to enjoy the profits while they last.
If I have seen further it is by stealing the Intellectual Property of giants.
- The test can take place at a place of my choosing
- I can use as much fuel as I like getting to the start point
- The driver doesn't have to come back
Space, here I come. Well, here comes the poor chap I trick into driving the thing anyway.FGD 135
There's no real need to say "power windows" here, because they don't have windows at all.
My beliefs do not require that you agree with them.
But...the parent didn't make the claim that anti-pollution devices increase efficiency, nor did he even begin to imply it.
"I zero-index my hamsters" - Willtor (147206)
I'm surprised that in all my searching I've not found anyone pointing out on of the MAJOR components to poor fuel economy: the way people drive.
People are so incredibly inefficient in the way they drive, it's no surprise that it's difficult to improve fuel economy (especially while staying profitable). Have you ever noticed that people love to race to the next red light? They accelerate like they're anxious about missing something, only to continue accelerating long after the point where they could coast to the light, and then slam on the brakes to stop....
What if: you accelerate slower, arrive at the next right light later, and just maybe it'll actually be GREEN when you arrive, meaning you wont need to slow down much (or at all), let alone stop.
Anytime you use the brakes you're WASTING money - both your brake pads & rotors, and the gas you're going to consume when you accelerate again. I rarely see people concerned about they way they drive in this respect, however.
One good example of how effective this kind of driving is can be found by checking out S04E04 (aired 30 May 2004) of the BBC car show TopGear - host Jeremy Clarkson drives an Audi A8 with a twin-turbo 4.2L V8 diesel over 800 miles on one tank of diesel. Granted, the driving style isn't entirely practical, but a lot can be gained without sacrificing quite as much as in the episode.
The smartest people in the world can only improve the things we use, not the people who use them.
No, I used to keep track. If you had a beat up old Dart that you just drove as an appliance that's different. If you had one that you kept in great mechanical shape, the mileage really improves.
/6 did great. So did my 67 Barracuda also with a /6. The 64 Dart GT not so great but that had a 318 V8 that would devour big blocks and new Mustangs. (This was 1995). The crap heap 1961 Valiant /6 I had was 15mpg or so.
Most people treat cars as an appliance. I really dig the old stuff.
My 1965 Dart GT
My NSU weighs about 1,200 pounds and that was used as an extreme. My basic point is, cars have improved why hasn't gas mileage? They weigh more and have more power and it's close to equal as stuff from the 1960s.
riding round the world on an old motorcycle
I don't want to hear any more about MPG. That's the wrong question. If it uses gasoline, that's a problem -- not a feature. How about it car makers? Where is my plug-in electric car? I'm ready to buy a plug-in electric car with, say, 100 mile range. That would satisfy over 90% of my trips. For longer trips, you could rent a car and still come out ahead, but we're a three-car family anyway. Maybe a plug-in hybrid could be okay, but those are pretty sparse too. I do live in Florida, so it does have to have an air conditioner, and achieve the range with the air conditioner turned on.
Computers obey me.
CO is not a "hydrocarbon". There'd have to be an H in there for that.
In every car I've owned that catalytic converter is inline with the exhaust, with no other couplings. I don't know where you're getting your pumped oxygen from.
My Dad's 1986 Camry got 42mpg on the highway. I've always wondered the same thing. Surely there's a market for light and not very powerful cars still.
I want some technical details. Instructions on how to build my own. Hell it didn't even say how fast they were going. Where the juicy information?
And dont forget that in the US at least, the size of the people in the car has also increased dramatically. ;)
I was so surprised to see that the teams were all WHITE. What a surprise to see NO blacks with their 'equal intelligence' on these teams...
Simple. All they would have had to do is give the car the mass of a tiny black hole, and let it fall to the center of the earth, and voila, thousands of miles with no fuel expended whatsoever. They couldn't allow this kind of cheating.
The only hard part would have been putting the chair on it for the 50kg driver.
It's rare that you're presented with a knob whose only two positions are Make History and Flee Your Glorious Destiny.
Don't underestimate the additional weight gained by larger window sizes!
And thats a 1986 astrovan too! You can do it too. Just make sure you start at the top of a big hill.
I think you're idea of the load on a car traveling a constant speed is off by a lot. I estimate my car uses a little less than 6 HP to maintain cruising speed on the highway. I backed that out by using the change in my MPG. An online formula for a different car came up with 7.3 HP @ 50 MPH and 20 HP @ 70 MPH (drag is v^3)
Probably the two most advanced "affordable" EV/PHEV projects right now are the Aptera (both the $27k Typ-1e and $30k Typ-1h) and the $25k Mitsubishi MiEV. You could probably get either by late next year, although you'll need to be tricky about it if you want it that soon (I'm getting my Aptera through a California intermediary). The Subaru R1e, also coming out in the same timeframe, doesn't cut it on range. The GM Volt will be $30-40k, with a late 2010/early 2011 timeframe. Another one to keep an eye on is the $25k VentureOne. If you don't mind tandem seating, it looks like a very fun ride. You may also want to watch Nissan-Renault and Think's offerings, and watch to see if Subaru decides to commercialize the G4e. All of these vehicles should be expected to be using long-life LiP batteries (10+ years with minimal degradation typical), with the exception of the G4e, which uses next generation, double energy density lithium vanadium oxide batteries (don't have info on their reliability yet)
:) ) for the electric-only version (not sure about the PHEV), energy efficient due to low cross-sectional area, and drives like a motorcycle -- the car automatically tilts into turns ("flying the road"). 0-60 in 7 seconds.
More detailed info on four of the less expensive models:
* Aptera: Space-age styling, lots of neat interior and safety features, 2 1/2 seater, extreme energy efficiency (~80Wh/mi; ~200 is typical for EVs). Efficient use of electricity means a smaller (and thus cheaper to replace) battery pack and faster charging on less power. Typ-1e gets 120 miles electric range while the Typ-1h goes 40 miles electric then gets 130mpg. 0-60 in 10 seconds.
* MiEV: More conventional styling, mainstream manufacturer, 4 seater, 120 mile range, lots of charging options. 0-60 in ~10 seconds (heard some conflicting info, but that should be approximately right).
* Volt: "Chopped" styling, mainstream manufacturer, 4 seater, 40 mile electric range PHEV, 50mpg after that. 0-60 in 8.5 seconds.
* VentureOne: Thin tandem two seater, 120 mile range (noticing a trend?
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
Isn't there an X-Prize that is pretty much exactly what you're asking for?
I read the internet for the articles.
Riiiiight....because the Pontiac GTO from about three years ago (don't know if they still make them) with a 6.0L engine isn't hideously oversized. The car was only slightly larger than the 2.0L Talon TSi I used to own, but had three times the displacement.
Although, perhaps the A.C. above would have been more precise to say "Hideously overpowered engines...", which would cover your 200 H.P. Honda and my Talon TSi.
MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
Of course if you get hit by a truck while in your Mustang you have a much higher chance of survival than you would have had in your old tin can Honda.
I read the internet for the articles.
Yeah -- we're all taller than you.
Miles per Newton
Modern cars get better mileage with the windows rolled up and the AC on than with the with the AC off and the windows rolled down. Of course the best mileage is with the AC off and the windows up, but the passengers might be done to medium-well at the end of the trip.
:P
This also depends highly on the car. I would figure this would be more true for larger cars with larger engines, where the AC consumes a commensurately smaller portion of the overall horsepower, with the implication that these aren't the most fuel efficient cars to begin with.
My Toyota Echo stands as a counter example, being at the very small end of the scale (and high efficiency for a pure gasoline ICE). My AC has a very noticeable impact on performance (I call turning off the AC "activating the turbo" when I'm merging onto highways), and also a very noticeable impact on fuel economy. Other cars may be better with AC on and windows up over 50 MPH, but I've measured my fuel economy in cross-country trips on interstates both with AC on, and with windows rolled down, and the AC-on fuel economy is about 2/3rds as good as windows down, from about 44 mpg to about 30.
Whereas I'm sure that if you're driving a light pickup with plenty of HP to spare, AC-on isn't as big a drain so going windows-up for reduced drag is probably better, so you're at 22 mpg instead of 20.
The enemies of Democracy are
Why are these vehicles aren't competitive with normal cars?
2,843.4 miles long - all the way down ?
My 200bhp 1991 Citroen XM V6-24 gets about 30mpg, and has an engine about as complicated as you'd expect for the early 90s - an early 1970s V6 block with an ECU with similar spec to a home computer of the 90s. I don't know why modern engines aren't much better than this.
Hey...you get 40mpg because you're driving a sewing machine dude :-)
http://en.wikipedia.org/wiki/NSU_Motorenwerke_AG
Just kidding. (I actually have the magnesium motor/axle-differential all together)..It's super light always wanted to make a kick-ass go-cart out of the thing. the NSU guys were doing some bleeding edge engineering back then. They made the first wankels too.
Poor economy from emissions controls is an artifact of what had to be done in the 1970's, before electronic engine controls, oxygen sensors, and three-way catalytic converters. The only way to reduce nitrous oxides in those engines was to retard the spark timing and stay away from a stoichiometric mixture, both means to reduce the peak combustion temperature (and power, and efficiency). To reduce carbon monoxide and unburnt hydrocarbons, the mixture had to be on the lean side of stoichiometric (excess oxygen), or on the rich side combined with an air-injection pump to burn off the residual fuel and CO in the exhaust manifold (where it does absolutely no good). It was quite a tight-rope act to meet emissions limits at all, so performance and economy were compromised. When the carburetor adjustment drifted even a little off the factory settings, things got even worse. Tune-ups were frequent, seasonal necessities.
Jump ahead to the mid 1980's. The three-way catalyst controls both CO and NOx best when the mixture is close to stoichiometric, and the oxygen sensor tells the computer whether the mixture is lean, rich, or just right, and the computer controls the fuel injectors to make it just right. Now low emissions coincide with good engine performance, and the feedback system makes sure it stays good as the seasons change and the parts age.
Those cars were mainly tin cans with low hp engine and a manual transmission; if it was getting 44 mpg's. In order to get any performance out of them you really have to work the gears, which Joe public refuse to do. That's why so many people favor 6 cyl cars in automatic. Honda for a while got a lot of heat because they didn't offer a 6 cyl in their line up. The biggest issue w/light cars were driving in the freeway w/mild to heavy crosswind. The car starts to oscillate developing its own harmonics. Sometimes you just hit your blinkers and change into the lane the wind wants you to go. Old VW Bug owners might know what that feels like.
Here's a photo of the winning car (the one on the right, #22), where are these 200 sq ft of solar panels you're talking about? There's also a better angle on the team's homepage here, no solar panels to be seen. Heck, that car doesn't even have 200 sq feet of surface area even if you counted the belly.
Did you know that while solar cars did compete, they were not allowed to win the grand prize?
Yeah, you're full of it. But at least you tricked a mod or two.
The enemies of Democracy are
...you could still buy LSD up until ... ah! those were the days!
Imagine that. There are tradeoffs involved when making things safer.
The fact is, right now, instead of letting people choose if they want efficiency, or maximum acceleration, or a steel cage that can crush a Hummer, everyone is forced into the steel cage of safety. If I could save 4000 dollars off the price of a new car and 6 MPG for the life of it, I might just choose to risk death if a truck were to hit me, and it should be my choice to make.My fellow Americans, let's restore the death penalty for child rapists. Let's do it . . . for the children.
If you read the article, the top competitor using gasline got 163.5 MPG. It does say they used Internal Combustion Engines, and it doesn't say what they did use but it's not gasoline.
Err, that's backwards.
You've got to go to the shell website, look for the Leader Board for the Eco-Challenge Americas, and then click on the link to the pdf which is here.
In it you can see that in the "combustion" class, the winner (same as overall winner) was the Mater Dei #22 car, at 2843.4 mpg, and that it used gasoline as its fuel.
The car that got 163.5 MPG was using LPG, not gasoline.
The enemies of Democracy are
Yeah, I had a 1989 Buick model with an inline-4, got 32mpg hwy. Now I have a 2001 Pontiac, v6, more torque & HP and a slightly bigger car. Still about 32mpg hwy. Even now on current models, I haven't seen numbers really beat the 30mpg on average looking at similar sizes. Why no economy or performance gains?
Well, you could tear out all the sound insulation, power everything, airbags, ABS module, ditch the A/C, chuck the entertainment/nav console or radio (and those heavy surround sound speakers), chop the roof a few inches (you don't need that extra head room do you?), and while you're chopping the roof - may as well use the sawsall to cut out the side impact bars in the doors and any extra metal folded and hydroformed in the frame for increased rigidity.
That should net you another 10-20 MPG right there, no mods really needed on the powertrain side. It's not that cars haven't developed better, more reliable, and more efficient engines, but rather that the car makers have made the cars more bloated and fatter (should be obvious to anyone who's had cars from the 1980's to 2000's) to make up for any gains that could be had by better technology. Now if at least one of them could be arsed to develop composite forming technology and start producing frames of carbon fiber (and lose at least 800-1000lbs), they could lead the fuel economy numbers easy without having to get crazy with powertrain development.
Good point. It's funny that the "Hybrid" econo-boxes get worse mileage than my Geo Metro. I don't know what the hang up is, but it does not seem to be getting better. Perhaps with gasoline prices going up something will break over and we'll see some improvement.
Drag power is v^3, Drag force is v^2, power is force distance / second = v^2 * v.
It's because they keep making cars bigger with better acceleration instead of improving Mileage
Curious about Storage and Virtualization? Check out
That may have been true in the early 70's, but not for any engine built in the last 2 decades. In the early days of pollution controls, you could only find low-octane unleaded gasoline (lead was used as an octane booster but fouls up catalytic converters). This meant low compression ratios resulting in low power and low efficiency.
These days we have better combustion chambers, high octane unleaded, electronic ignition with knock sensors, and most recently gasoline direct injection. Compression ratios over 10:1 are common. Even the VW/Audi 2.0T turbo engine has a 10.3:1 compression ratio.
Yeah, larger window sizes equals more fastfood that can be passed thru to the inside of the car where the rest of our fat-ass american society can scarf and binge all day long on carbs and grease. mmmmmm good ole american non-home cookin'.
If our fuel efficiency can increase prices will decrease, that means I afford another triple-heart-attack-grease-ball-burger to go with a side of thunder thighs.
What? Howcome you didn't add 18 more cup holders? Where is the contest for designs with more cupholders that can hold those 3 liter bottles of soda?
Sorry for the tangent! Go team!
ZERO ZERO ONE ZERO ONE ZERO ONE ONE! Just brushing up for my next big invention: Ethernet over Voice (EoV)
Thanks for the info. It's really tricky passing emissions standards in the pre-catalytic converter days. Until the late 90's, motorcycles with their smaller engines could still pass EPA using the same technology: lean mixtures from a fixed carburetor.
After that in the early catalytic converter days, high octane unleaded was hard to find which meant low compression ratios which hurt power and efficiency.
the system needed in a car could be significantly smaller
It could be, but you have to remember that there is next to zero insulation in your car. The metal and glass frame is sucking in heat from the outside quite fast, if a unit is too weak, it'd never keep up.
Google isn't helping a lot here (I've been looking for 15 minutes or so) but I found this posting (ignore the guy who wants "colder freon") from 1995 stating that car ACs are 3 to 4 tons http://www.yarchive.net/ac/humidity_removal.html which is in line with what my father told me when I was a little kid. Ebay says "The average factory installed auto A/C unit is rated at 1-3/4 ton." http://reviews.ebay.com/Frequently-Asked-Auto-A-C-Questions-Part-2_W0QQugidZ10000000000932442
"One ton" of air conditioning power is 12,000 BTU/hr, which wiki (sorry, too lazy to do the math myself) claims is 3517 watts (not counting the inefficiency in converting electrical watts to actual heat transfer, meaning actual power required to get one ton of AC is higher). Central AC seems to average about 3 tons, based on the prevalence of that number in example calculations like this one.
Based on these numbers, your window unit is significantly weaker than a car AC system.
If I have been able to see further than others, it is because I bought a pair of binoculars.
It's just like software bloat. Car models get bigger over time. A new Honda Fit is a closer match to your 92 Civic. It's probably a little smaller outside, but it matches the old Civic for power, comfort and interior room.
BTW, the EPA adjusted the mileage test for 2008. MPG is down across the board because the old mileage test was unrealistic and didn't match up with real world (read lead-footed) driving.
http://www.fueleconomy.gov/feg/ratings2008.shtml
Honda Fit got 38 mpg highway under the old test, 34 mpg highway under the new test. If you drive it like a granny, you'd still get 38 mpg.
I don't understand why modern cars get such lousy mileage. I have a 2005 Malibu with a 200hp V6 and it gets 35MPG highway when treated well, 32-33MPG when driven more aggressively. I average more like 28MPG with mixed city/highway driving. Seems like the modern cars are actually doing fairly well.
For example, to maintain low NOX emissions with your standard catalytic converter, you need to maintain an air/fuel ratio of approximately 14.7/1.
Under light load to minimize fuel consumption, you'd be better off leaning out the air/fuel ratio (injecting less fuel), but unfortunately NOx emissions tend to go sky high when doing so.
You can get around this by using a special exhaust devices which can trap NOx emissions, run the engine rich for a bit to burn off all the NOx emissions and then go back to lean burn operation. The Honda Insight did this, but I don't know of any others.
Diesels especially suffer from high NOx emissions since they regulate power by varying the amount of fuel injected instead of using a throttle body. This is why are only recently are a few diesel cars trickling into the market place this year with exhaust treatment systems specially designed to reduce particulate and NOx emissions to gas-car levels. Cold start fuel economy is also markedly lower for the same reason - cars intentionally burn EXTRA fuel to heat up the cats faster so that they end up emitting less overall NOx and HC emissions. If emissions weren't an issue less fuel would be burned. The Prius for example is notorious for typically delivering a meager ~25mpg during the first 5 minutes of use. The 2nd 5 minutes will be double that.
You could probably improve fuel economy 10-20% across the board in gas cars if you didn't have to worry about NOx emissions. In fact, this is one reason that hybrids improve fuel economy. Besides stopping the engine when no engine power is required, they also let you operate the engine in the most efficient and lowest polluting engine operating conditions. For example, if you get a Prius going a steady 20 mpg on flat land, it will transition between running solely off the battery/generator and turning the engine on to charge the battery/generator while getting over 100 mpg.
To clear up a common misconception with hybrid cars people often ask - why doesn't it run longer/faster/more on electric power? You have to remember that the only electric power that is "free" is the power gained through regenerative braking (that power is normally lost 100% as heat in a conventional car). You also have to remember that charging a battery and discharging a battery is not 100% efficient and most of your battery charge (except for the little bit that comes from regenerative braking) still needs to come from the gas engine. Some people will install an EV mode switch and then force their hybrid to run for extended periods of time on battery - then complain that fuel economy went down! That happens because at some point in time you have to recharge the battery - and by forcing the car to stay in EV mode you then force the car to charge the battery when it's low - no matter if it happens to be most efficient to do so at that point or not.
FFS, I can grab a gallon of gas, jump on a skateboard, and push the thing however thousands of miles I want. My "car" will have infinite MPGs!
All if this hippie wanging is pointless and useless until you get something that's actually practical and available for mass purchase that people will actually *want* to buy.
Right, it's because of McDonald's drive-throughs that cars are heavier. Well, when people are *in* them.
Random Thoughts From A Diseased Mind (Not For Dummies)
Why is it that the proponents of "one nation under God" are so eager to get rid of "liberty and justice for all"?
I can get 3,800,000 mpg easy - I walk 1 mile to work, then I spill 1 drop of gasoline on the sidewalk. 1 mile / 50 microliters = 3.8E6 mpg. That's basically what they're doing here. (The gasoline contributes only a fraction of the total energy used).
Actually my convertible (2006 Toyota Solara) gets better mileage with the top and windows down (28.2 MPG) than it does with the top up and AC on (27.6 MPG)
Why is it that the proponents of "one nation under God" are so eager to get rid of "liberty and justice for all"?
I have a nine year old motorcycle with a 1.4 liter engine that makes a measured 200 rear-wheel HP, naturally aspirated. That works out to close to 240HP at the crank. The bike has 20,000 miles of real driving on it and it still runs like new. The 100HP-per-liter that the S2000 makes isn't very impressive. Motorcycles hit 100HP-per-liter in the 60s, maybe sooner. I know my old 1985 RZ350 made over that, my 1973 YZ250 also tops 100HP-per-liter.
Actually, I just looked under my 1996 Oldsmobile Ciera recently and was suprised to see that there is indeed a stainless steel air injection line running into the catalytic converter - at least I'm pretty sure that's what it does, what else could it be?
The back pressure is largely additive: its in addition to the muffler and resonator. EFI does not choke the engine like a carb; it always runs at optimum fuel mix. It just might be more fuel and less air when the engine is cold. It doesn't really "waste" it. Also, the emissions system cannot ADD to gas mileage, so it cannot pay for itself in terms of it. If you take it out, the computer will simply correct the fuel mileage.
My car, when it was new, got 38MPG(actual reading on a trip to Ohio) on the highway and generated 155Hp. You'd be VERY hard pressed to find such mileage results today.
Anyway, YES, EFI cars have far less emission control systems than older carbed cars. Less PCV and vacuum equipment, smaller or nonexistant air pumps - but the catalytic converter will always be there. The reason is that most of the the converter takes care of is not a part of the combustion of fuel- but is rather the result of what happens to the rest of the air (nitrogen and such) in the extreme heat and such. Efficiency cannot affect that - in fact, higher operating temperatures of modern cars have made it worse.
Nitrous oxides, for instance. There's no nitrogen in gasoline.
I don't have the exact statistics to hand for the USA, but a study in Sydney, Australia (and by global standards Sydney's air is very, very clean) suggested that urban air pollution, mostly from vehicles, caused around 1000 premature deaths every year. That's at least triple the number of deaths from car accidents.
So, even if they do increase fuel consumption a little, anti-pollution gear is a very good thing.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Your mileage may vary... it's truly appropriate an expression here.
Instead of requiring "this and that pollution control measures", the law should write "the maximum pollution level in the exhaust is this and that".
Now it becomes up to the automotive industry HOW to reach this. Either using catalytic converters, filters, etc, or improving the engine itself, or both of course. If they manage to invent an engine that burns its fuel so clean you don't need these filters: great, now we have a very efficient and presumably cheap solution, as it doesn't need the extra equipment to meet the law.
Now I don't know the exact laws, but I have never heard in Europe about specific equipment requirements, only about specific emission levels. Which is how it should be.
That's the thing of it, isn't it? Most power-enhancing modifications will also improve fuel economy. Because power is directly related to the percent combustion you're getting out of the fuel: if your combustion percentage is only 85%, then you're only getting 85% of the energy out of your gas. You squeeze more ponies out of an engine by improving the combustion rate, and improving the combustion rate improves fuel efficiency. Having better efficiency means better fuel economy, unless you're driving the piss out of your car. :)
If you believe everything you read, you'd better not read. - Japanese proverb
If you look at just cars, a 69 charger is about the same weight as the 2008 charger for instance. It's the trucks and SUV that are >2 tons--and there's a lot of them running around nowadays compared to 20yrs ago.
Though cars are creeping up on weight: cars are getting heavier because of materials to decrease NVH. You can tune as much into the suspension, but a light car will always rattle, toss and bump in most situations (a gokart comes to mind)--yet, solid iron (i.e. heavy cars) will not rattle as much.
Who's nobody? Much of the world (such as Europe and Asia) can buy a 600cc class of cars that gets similar mileage as the Honda HE.
The U.S. attitude on such cars will probably have to change as gas approaches (and goes well beyond) $5, $10, or $15 a gallon...
New cars use a lot more material due to increased safety standards and consumer demanded features. For example, a 1973 Honda civic weighed in at 1500 lbs; fast forward to 2008 and the civic now weighs in at 2700 lbs. Engines have gotten better, the efficiency gains are used to create more powerful engines to move around a reinforced chassis filled with power everything.
not sure what batteries/location your using. Where I live, more than half the cost of electric is in the delivery/line charge. Then you lose 15% in the charger and another 30% to the lead acid battery.
So while at the power plant rock in efficiency, it doubles in cost getting to my house, then I lose half getting into and back out of the battery. I am left with 1/4 what it started out at. At 120,000 BTU per $3 gallon of gas, or 140,000 BTU per $3 gallon of diesiel I get 60,000 BTU per $3 of Electric. My understanding is Gas engine are 70-80% efficient. Since I don't travel in town, I'll take the 50MPG diesiel car over any electric charge so far.
Well, kinda. An IC engine is running most efficiently when it's cramming as much air and fuel into its cylinders as it can, burning as much fuel as it can, because if it's *not* doing that, then you're carrying around more engine than you need.
So, all else being equal, if you want to optimize for fuel efficiency, you go for an underpowered engine. Yes, acceleration will suck, but the engine will be spending proportionally more time at peak efficiency, because you have to keep the thing floored just to pull away from a stoplight. Take a look at cars that have optimized for fuel efficiency; things like the Geo Metro could get 50mpg 15 years ago, because they had lawnmower engines in them. Sure, you've got to run them flat-out to do anything with them, but when doing that you're in the most efficient operating regime for that engine.
A 400-horsepower engine that you never take above 3000rpm is going to kill you in terms of mileage, because you're barely straining it, and you're hauling around a lot of dead weight.
Now, increases in *specific power* mean you can improve fuel economy, because now for a given design peak power, you can use a smaller plant. But modifications that simply increase peak power are going to waste fuel, all else being equal.
One of the ways to improve engine efficiency is to increase the compression ratio. However, high compression also increases NOx production because the pressure and heat is high enough to break down atmospheric nitrogen.
Where I live, more than half the cost of electric is in the delivery/line charge.
:)
It doesn't matter how much is in the "delivery line charge"; cost does not equal efficiency. In the US, the average transmission efficiency is 92.8%.
you lose 15% in the charger
AC Propulsion's 20kW charger is 93% efficient, while their 150kW charger is 90% efficient. That's pretty typical for non-inductive chargers.
and another 30% to the lead acid battery.
Lead-acid battery? Lol, what do you think we're talking about here, golf carts? NEVs? Even Firefly lead acid batteries are simply unsuitable for these sort of tasks. Way too short lifespan, way to inefficient, way too low energy density. We're talking about lithium ion variants. Lithium ion batteries are over 99% efficient (that's why they charge and discharge cool).
So while at the power plant rock in efficiency, it doubles in cost getting to my house
Please learn to separate the concepts of "cost" and "efficiency".
My understanding is Gas engine are 70-80% efficient
Try about 20%, give or take.
It's okay to be unfamiliar with this topic. Just educate yourself so you're more informed for future debates and we can talk some more.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
You can't outright discount gasoline, though. Gasoline engine innovations are quite important right now, where relatively few reliable sources for on-the-go alternative energy exist.
Given that the distribution systems for gasoline are already well in place, an efficient petrol-burner may end up being a far better ecological and conservational option than even a more efficient alternative-energy car. If a car can't fit into the budget and lifestyle of a large enough group of people-- as well as be successfully marketed and sold as such-- it won't have the adoption to support its production, and have as little real impact as if it was never made.
Information wants to be free.
Entertainment wants to be paid.
You just want to be cheap.
sorry, but in a established market like this, cost pretty much does equal efficiency, except in this case thanks to gov't involvement in things like Rural Electrification Act even this cost is subsidized. After all all the copper that is having to be added took electricity and oil to mine, process, deliver, install, and maintain. If this were a young industry just growing, I would think otherwise, it is not.
ok 45% is the efficiency the power plant would hit, and 20% was the "typical" vehicle total use. My drive not getting much gain from regen, I am not getting enough gain their.with 300 typical charge cycles for a lithium battery, and a large enough volume of a metal that reacts very badly with watter. Someday, but not today.
One word: Torque
A few more words: Your motorcycle generates very little of it.
AntiFA: An abbreviation for Anti First Amendment.
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
91 octane is pricey? Wow, there really IS somewhere with worse petrol than Australia, our is 91 standard and most premium is 95 / 98.
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
And then, of course, you have the fact that you don't leave your lounge room parked in the hot sun for hours, then expect it to be nice and cool 20 seconds after you hop in and start it up.
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
More info, please. Two-stroke or four, for instance, is kind of important.
Can you be Even More Awesome?!
sorry, but in a established market like this, cost pretty much does equal efficiency
Not even close. We could run a superconductor from here to the moon, and it would be 100% efficient. It'd cost an *Utter Fortune*, but it'd still be 100% efficient. You're trying to equate two concepts that are *not* related. The cost of power transmission infrastructure has nothing to do with how efficient it is.
After all all the copper
Power transmission infrastructure is mostly aluminum and steel.
ok 45% is the efficiency the power plant would hit, and 20% was the "typical" vehicle total use
Which means that EVs are a lot more efficient. As pretty much every peer reviewed study on this topic has stated. Which you'd know if you were debating a topic that you actually knew something about.
with 300 typical charge cycles for a lithium battery
Did you notice the word "variant" above? Again, you're out of your league here, so I'm going to have to back up and explain some basics to you. Li-ion now covers a whole family of batteries. Traditional li-ion batteries use a lithium cobalt oxide cathode and a graphite anode. The cobalt is all-around the most problematic element. It's expensive and it likes to lead to runaway decomposition and various problems that shorten lifespan. There are a number of alternatives -- for example, spinels. The most popular replacement cathode is LiP -- lithium phosphate variants, usually lithium iron phosphate. The energy density is reduced (although still better than NiMH, and far, far superior to lead-acid). In exchange, you get very long lifespan -- A123 rates theirs for 10+ years and 7000+ cycles, and even then, that only means you've lost 15-20% of the capacity. They're also very fire resistant. It's a beautiful battery chemistry for EV apps; almost all new highway-speed EVs are using it. A notable exception is Tesla, which uses traditional li-ion since it's currently cheaper (although won't be once LiP is in mass production) and because their customers can afford replacements. Another options competing for market share are titanate chemistries, lithium vanadium oxide, and Argonne lab's layered cathode. In the future, there's silicon nanowire and tin nanoparticle anodes for extreme energy density.
Again, you really need to read about this topic before you debate it.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
Not quite 100 mile range, but cheap - very cheap. http://www.smart.com/-snm-0164329964-1153205850-0000017610-0000003413-1154020467-enm-is-bin/INTERSHOP.enfinity/WFS/mpc-uk-content-Site/en_UK/-/GBP/SVCPresentationPipeline-Start?Page=issite%3A%2F%2Fmpc-uk-Site%2Fmpc-uk.com%2FRootFolder%2Fsmart%2Fsmart_news%2Fsmart_news_2006%2FsmartEV_news.page
You sir, I point to xkcd.
Mmmmm... Zombie Feynman.
Are you a physicist, perchance?
It's really not hard to beat those mileage results. My Prius is averaging 46mpg. Civic Hybrid will average above 40mpg. Toyota Camry Hybrid will average about 35mpg - not hard to beat 38mpg if driven judiciously. The reason is that most of the the converter takes care of is not a part of the combustion of fuel- but is rather the result of what happens to the rest of the air (nitrogen and such) in the extreme heat and such. Efficiency cannot affect that - in fact, higher operating temperatures of modern cars have made it worse. While higher operating temperatures can raise NOx emissions, I dare you to find one modern car with higher NOx emissions than it'd older counterpart - even with the catalytic converter removed. Peak operating temperatures are typically limited by the knock resistance of the gasoline - which is still 87 octane. Modern vehicles are able to raise compression and improve efficiency without knock by virtue of having highly optimized combustion chambers which quickly burn as much as possible of the air fuel mixture. If NOx was a concern, they could inject a tiny bit more fuel to compensate - the extra efficiency from being able to run higher compression should compensate.
You're kinda forgetting a few things.
Typically cramming as much air/fuel as possible in the engine is not the most efficient for a number of reasons - but primarily because doing so generates so much excess heat as waste that you must add extra fuel to try to keep things cool.
For example, your typical gas engine will produce the most power when running an air/fuel ratio around 12.5 to 1. But you could make slightly less power but do so more efficiently by running slightly leaner, around 13.5 to 1.
But realistically, most engines will run 10-12 to 1 during WOT, especially at high RPMs to keep things from melting down.
Ideally, you would run WOT all the time, and simply adjust fuel and RPMs until you had the power level you wanted. Low RPMs because friction rises more or less linearly with them and naturally the least amount of fuel possible. You know, run it like a diesel which has no throttle body. But unfortunately gas engines don't run well at extremely lean air/fuel levels and will typically misfire - not to mention generate large amounts of NOx emissions when running leaner than stoich which your typical catalytic converter will not be able to clean up.
A compromise is to run a small engine with turbocharger. This way for normal sedate driving you drive the car like a regular small car. You'll use a bit more throttle and as such, pumping losses will be lower than a larger engine with the same output capacity. And when you need the power, open the throttle and close the turbo wastegate to get that burst of power to pass that truck.
Your octane is measured on a different scale, if it's anything like Europe. 95 RON is something like 91 MON and 98 RON is something like 93 MON. You can even buy 94 MON in Canada.
Well well, you learn something new every day... I though it was odd that there was something good about buying petrol in Australia. Recently it's been as high as 156 cents/liter for 98 RON fuel, which works out (if Google's not lying to me) at $5.44/gallon. How does that compare? I seem to recall complaints a few years ago that the civilisation as we know it couldn't exist with petrol over $3/gallon...
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
-- Intelligence is soluble in alcohol
If my numbers are right, 2843 MPG is 1208.7 km/liter. Last year, a French team had 3039 km/l, but if memory serves, 3 years ago there was a Japanese team with more than that (3836 km/l, or 9023 MPG). These guys would have made 14th in Europe. And this is news?
We had the same kind of misinformation 2 years ago.
That's the beauty of IC-electric hybrids (the technology, not necessarily the cars). You can do all kinds of neat stuff with engine RPM's when you've got an accumulator for mechanical energy. Submarines have been doing this for at least a century.
The same thing applies to every form of on-demand power system, electric power plants included. Wind power and solar are terrible at giving a constant and predictable power output, even when distributed over large areas, since you only get the option to throttle them. Hook them up to a pumped storage system, and, while you can't control the MWh/yr, you can at least decide when you get them.
Lotus Elise:
Curb weight 860 kg (1896 lb)[6]
lot closer to that CRX's weight, with about 100 more hp
I suggest people look at the UK competition, where the winner got over 10000 mpg (and there were 13 that got over 2843)...
Drivers had to weigh at least 50 kilograms = drivers must weigh => 50 kg.= drivers must weigh => 100 pounds. So why is this modded "informative?" Sorry it's too early for me to look up the code for the "equal to or greater than" symbol.
nope, you'd get 100% of the electrons through it. But in the real world cost matters, with cooling costs, and atmospheric drag, this line would take all the energy from the orbit of the moon bringing it to the ground.
OK, I'll admit if you don't want to count manufacturing costs, or maintaince costs, but only energy in use. EV's are then more efficient. Gas is still much cheaper. look at this car, according to wikipedia Lithium costs 2.8-5 Wh/US$ to buy, get 300 to 1200 cycles. Multiply that out, battery cost of lithium polymers is going to be about $.25
I am test engineer in charge of a 3000 Hp Hybrid vehicle prototype running some very hot Sodium batterys, that while kept hot are over 99.9% efficient in charge cycle, and their energy density is actually greater than diesiel fuel per weight. Trust me, I know their are no batterys available for purchase by any person, or a company for mass production that has energy density, cycle times and efficiency for a reasonable cost per Kw Hr. It is a hope, and maybe soon, but if you car about economics and the environment, EV is not yet it.
Not exactly the same engine. We're only getting a 3.0 liter version in the 3-series. We aren't getting any of the 1-series diesels.
At present, there are publicly announced plans for ANY automaker to bring out a diesel in a US car smaller than a Jetta SportsWagon or an Honda Accord.
The trend towards tank-like cars is caused by the "safety arms race." This started in the mid/late 90s as SUVs gained in popularity. Now your car has to be heavy and overbuilt because other cars on the road are heavy and overbuilt, and if you're scared to death like the car industry, insurance companies and governments want, you want to have a well-armored car to stand up to impacts from other well-armored cars. This gets worse and worse and eventually the new Mini Cooper comes out at 2500lbs, and that's considered super-light. And you want that added safety, THINK OF TEH CHILDREN!
"When information is power, privacy is freedom" - Jah-Wren Ryel
A good example would be the Honda Insight (hybrid). It was available in a ULEV 5 speed as well as a SULEV CVT transmission model. The 5 speed was EPA rated for bout 70MPG, while the CVT was rated for 56. The difference wasn't in the trans, but in the engine; the ULEV model was able to go into a 'lean burn' mode with a air-gas ratio of about 28:1 when the engine wasn't under load, while the CVT was still constrained to run at ~15:1. Burning gas at the 28:1 ratio resulted in higher "NOx" levels, and the ULEV car couldn't pass the California SULEV standards, so the CVT model was produced to satisfy that requirement.
Additional note: in a 'stick hybrid', the driver gets to decide (through early shifting) to put more demand on the electrical motor than the gas, while the CVT driver is stuck with the pre-programmed ratios. This allowed the stick driver to adjust their shifting pattern on current and future driving conditions, while the CVT owner cannot.
Take one reasonable small car. Add a thousand pounds of "safety" equipment. Then add another 800 pounds of "emissions" equipment. While you're at it, throw in an air conditioner, power steering, power seats, a sun roof, and a few other details. Then beef up the structure and suspension enough to carry all that extra weight. Then evaluate the acceleration and braking performance, and beef up the motor and the brakes to accelerate and brake all that extra weight. The bigger motor needs more fuel to go the same distance, so there's more weight in the fuel tank, too. Then your marketing people decide they want 0-to-60 in 6.3 seconds, so you offer an optional larger motor, which requires a stronger transmission, even more structure and suspension, and yet more fuel. Then the optional motor is made standard, along with the automatic transmission. Add a hundred pounds here and a hundred pounds there, and pretty soon you're talking about some serious weight.
The engineers do their best to reduce weight wherever they can. But, when it's all said and done, an average small car today weighs twice as much as similar products from forty or fifty years ago. All those "features" add mass and inertia which has to be accelerated and decelerated.
-Turkey
"I have a 460hp (modded) car that got 38mpg on a LA-San Diego round trip. At the same time, it gets about 2mpg at full throttle and top speed. There is nothing wrong with modern engines, but if you have a ton of power and habitually use it, you will pay in fuel."
=====
I have to ask..is that a power adder car? Turbo'd? I find it hard to believe an all-motor car can pull that kind of mileage.
On my side of the fence, I have an modified LS1 all-motor car that that was dyno'd and calc'd at 498HP at the crank. Of course I get alot of lose with an automatic trans (build 4L60 with a Vig3600 stall thats actually seems to stall closer to 4000RPM). Oh.. and as for cats? What cats? Havent run em for years. Useless power robbing devices as far as I'm concerned. Exhaust is just Hooker long tubes/collector/ORY pipe/I pipe/dump/when capped, passes thru dynomax muff.
I bet your curious how I do on gas? On short daily trips (2 miles one way to train station, in the winter) I will get about 120 miles..TO THE TANK.
But on any trip over 10 miles on the highway I can do mid 20's easily in OD. Its really the short trip/Big Converter that kills the mileage on the beast. The car isnt even warmed up by the time I make to to the train station. The car is just running in an open loop at that point. But hey, if I dont go anywhere other than work, a tank of gas still lasts a few weeks anyway.
Considering the car is built for drag racing, I'd say it does pretty darn good on the highway. I get better mileage than alot of SUV's and some cars. If I were to go with a smaller converter, say 2800 or back to stock at 1800, I suspect I'd be doing 18-20 in the city.
Big HP cars dont necessarily have to be looked upon as 'evil'.
I'm impressed by your mileage/HP numbers. As stated, mine could be MUCH better if it were not for the trans setup and short trips.
An M6 (manual) could solve that, but when drag racing, Automagics rule the roast. Much more consistent and easily tweaked via software.
"You can tune as much into the suspension, but a light car will always rattle, toss and bump in most situations (a gokart comes to mind)--yet, solid iron (i.e. heavy cars) will not rattle as much."
Try a set of subframe connectors. Trust me, they do wonders on uni-body cars...
You failed to understand what I wrote, which is why you fail to understand why it's modded "informative". Also, 50kg is approximately 110lbs, not 100lbs.
"The past was erased, the erasure was forgotten, the lie became truth." ~1984 George Orwell
There are a ton of LIGHTER modern cars. In general, practically the only things which have gotten significantly heavier are the honda civic and the mini. Well, that and every volkswagen. Problem is, all of them were deathtraps (yes, all classic VWs are primarily good ways to die and secondarily economic vehicles) and many of them can get just as good mileage today. People don't buy those cars BECAUSE they are deathtraps. Meanwhile, the next generation of lightweight vehicles is coming, like the SMART cars (well, they're still coming here, because the smallest one would get wiped off the road) and if it makes it to market, the Loremo.
VW built the rabbit diesel (55mpg) and Honda built the CRX HF (55mpg on gas) and both were total deathtraps in which you can't even properly accelerate for the freeway unless it's on a downhill. These are not victories. They are bad stopgaps.
The average American car is dramatically LIGHTER than it was in the past. I owned a 1960 Dodge Dart, which allegedly had a 4700lb curb weight (not GWVR, either.) This was a 19.5' long, 6.5' wide car. The later Dart was far smaller and was MUCH lighter. Today's Dart is the Neon, unless they've finally superseded that thing, I don't pay much attention. It's FAR lighter, although it's also the most unsafe modern car on the American road. The side impact is so bad they wouldn't rate it. Well, that was last year, maybe it improved...
The Japanese cars have gone up in weight, but aside from the few exceptional high-milers which pretty much all came from Honda, their mileage has improved. I have a 1993 Subaru Impreza LS (2750lb AWD 1.8l 110hp 110ft-lb) which gets maybe 26mpg freeway. You can actually get a turbo Impreza which weighs some 500lb more, has literally twice the power and even has more displacement, and still gets almost another 10 mpg.
Older cars had A/C too, and the A/C equipment was dramatically heavier back then. Even the hoses weighed twice as much then as they do now, with hard lines as likely to be made out of copper as aluminum and with compressor castings made of iron. Some of the old compressors even had a V-twin design with a sump! That compressor probably weighs more than many dirt-bike engines!
With that said, there ARE some American cars that have INCREASED in weight since the sixties. To be fair, though, they're pretty different cars. For instance, the 2008 Dodge Charger weighs about 50lb more than the 1969 Dodge Charger - but the original was a two door hardtop and the new vehicle is a four door, which means it's not a Charger at all. The weight is about the same as a four door 1969 charger would have been, if not less, and it still gets significantly better mileage. Not as much better as if it had used a turbocharged V6 with variable valve timing and coil-on-plug, but still a hell of a lot better than the carbureted monsters they used to use.
By the way, modern engines are generally not much heavier than the older engines; pretty much everything back in the day used an iron block, while anything credible from today uses an alloy block unless it's in a truck (and maybe even then.) Ford and Chevy have both gone all-alloy for car engines, well behind basically every import manufacturer; many vehicles also include aluminum pistons, further reducing weight.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The best thing you can do is go with a smaller engine and add a turbocharger. The turbo lets you burn more fuel if you want to, and carry less engine around. It's a win-win situation. Low pressure turbos (under about 7 psi) are common in Europe, on little 1.2 and 1.3 liter engines and such. Because they have tiny engines and aren't hunting performance the turbo is small and reliable. I had a 1984 300ZX Turbo with over 200,000 miles on it; it was poorly maintained and still ran like a top because it ran a whole 7 psi (and thus needs no intercooler which adds weight and complexity.)
The great thing is that you can run on crappy gas even with a turbo, because you can wait to advance the timing until RPMs are high, and static compression is low (making the engine easier to start, and allowing a smaller starter motor, thus further decreasing weight.)
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The issue is not one of "HP to spare". The issue is that the Toyota echo is a piece of shit deathtrap (no offense man, but it's a beer can. I've studied auto body and paint, and I've seen what happens in a collision, and I would never own one.) It's a poorly engineered car from stem to stern. The aerodynamics are also pretty good but not what they should be; at 0.29 it's a little worse than a 1989 Nissan 240SX (.26) and notably worse than a honda insight (.24). This is mostly due to unnecessary (and IMO ugly) styling cues on the front end and the tall profile, which makes this lightweight car with cookie cutter wheels blow around excitingly in a crosswind.
A truck with the aerodynamic profile of a serbian bunker is not going to lose much mileage with the windows down. My 240SX got around 30 mpg (without AC) with the windows up on its truck motor (KA24E, 2.4l SOHC 8.6:1 compression ~155hp, ~155ft-lb) and probably 28 with the AC on. Open the windows and you can FEEL it. But it's a super-aerodynamic little car.
I didn't look much at the A/C design on the Echo, but I suspect that it has too much A/C and too-cheap A/C components (like the rest of the car - remember, I've seen every inch of this lemon torn apart) and the system is simply overdesigned and inefficient. I think the Echo has a little too much height over the beltline, and the insolation factor means you need a lot of A/C if that's your cooling technology.
Some of this is speculation and some of this is certainty; you can pick out which. But in my 1993 Subaru Impreza, you can easily feel the difference between windows down and A/C on, and it's not in favor of the windows. I have informally experimented via the "hill" method, which is to say that my car can accelerate up certain long hills near my house with the A/C on, but not with the windows down. Obviously, at lower speeds this changes, but that speed varies for every car and in fact for the day itself. Even a tailwind will reduce this tendency!
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I forget where I read it, but apparently a truck with the tailgate up usually gets better mileage than one with it down or even with one of those cargo net things instead of the tailgate, because an air pocket builds up inside the bed and the air mostly flows over it, but if that doesn't happen you get massive turbulence behind the cab instead. The same principle is probably at work in your 'vert, and the air probably has to travel a shorter distance to flow over the car than with the top up.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I haven't bothered to look in my notes from my Automotive A/C class; I am ASE certified in Automotive A/C but never worked in the field and I'm forgetting my facts and figures. One thing I do remember is that Automotive A/C can draw as much as 5 horsepower from the engine through that little belt; it's about 3.72 kW. So it makes sense that you could have about 1 ton of A/C in a car (with inefficiency.)
Incidentally, most systems ARE capable of running on a variety of refrigerants, if you just flush the system and change the dryer (a job which ranges from simple to oh my god depending on the car. You have to remove the hood and all A/C hardlines of a Ford Taurus, but only the headlight of a Mercedes W126, for example. Never work on a Taurus if you can avoid it. Actually, never work on a Ford if you can avoid it.)
The problem isn't just the lack of insulation, by the way. The biggest problem is insolation through the glass. Fancy-schmancy cars actually have an IR sensor pointed at the driver (and maybe the passenger) and a sunload sensor on the dashboard so they can determine how much heat is occurring from insolation, and increase cold air output to compensate.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Pfft, my previous car was an 87 Toyota Tercel. Why would the epithet "death trap" or "beer can" be offensive to me? I obviously seek out this kind of car.
The enemies of Democracy are
My 2007 TSX with 205HP got around 38.2MPG Highway on a 327 mile trip last weekend. But some people will drive the same car and get 27 and they recalibrated the tests so I don't know how the Oldsmobile Ciera compares at 70MPH highway driving.
Sounds like you are missing the point to me. They take the more boring and stodgy parts out and show you the very heart and soul of real science. Real scientists understand it's brain candy science and those who don't understand real science get a good hint and *Shock, horror* might actually get interested in it themselves, all without being just stupid and meaningless.
Sure, someone could make a show that chronicled exacting careful laborious and boring parts that took years to make and no one would watch, but what would the fricking point of that be?
nope. You tell me, what is the point of drawing inaccurate conclusions? If you admit mindless entertainment then I will agree with you. Less damage would be done to an already ignorant public if you just went back to watch farting cartoons.
That mythbusters episode really repulsed me.
/.ers seem to think the show is entertainment, I find most people seem to think it is factual)
1. Lets take a shape that has so much aerodynamic drag that opening the window won't have a great effect.
2. Then lets run it at a low speed, where parasitic drag is the lowest.
3. Then, lets find a vehicle with an air conditioner that could cool a house.
4. Then instead of finding a comfort point, turn it on full so the occupants have to wear winter jackets.
DUH - the open window(s) appear to be more efficient. This is offensive to the extreme, AND CAUSES HARM TO THE ENVIRONMENT as 80% of the US now thinks that it is more efficient to open windows, and now some may do so on the HWY.(while
(If this test had been done on a car with low drag at 60 or 70, the result would have been SO different)
In my experience, the Fit got good(well, at least OK) gas mileage around town, no complaints.
On the HWY the fuel mileage was not much different than large cars I've driven.
I believe old civic was better, I blame the Fit for excessive drag, but I don't know what the real problem is.
That's funny! When I was in Scotland I mentioned to the guy at a petrol station that our lowest octane 'petrol' was 87. His reply was, "Why, that's paraffin!". Theirs, as I recall, was 95 - RON, MON or (RON + MON)/2, I don't know.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
nope, you'd get 100% of the electrons through it.
Which is known as 100% efficiency.
But in the real world cost matters
Which nobody is denying.
with cooling costs
Cooling costs in space are zero. All you need is a proper reflector/radiator setup.
and atmospheric drag, this line would take all the energy from the orbit of the moon bringing it to the ground.
Then just picture it running through empty. This is a thought exercise. There is a huge distinction between "cost to build" and "efficiency of operation".
OK, I'll admit if you don't want to count manufacturing costs, or maintaince costs, but only energy in use
The energy used in building power transmission infrastructure is utterly dwarfed by the three-phase loads it carries in its lifespan.
Gas is still much cheaper.
No, it is not. An Aptera goes, with my current power rates, half a penny per mile. Show me a gasoline car that does that. At $3/gal, a 30mpg car costs $0.10 per mile.
Gasoline is an *incredibly expensive* power source. Joule per joule, it's *30 times more expensive* than powder river basin coal, for example.
look at this car, according to wikipedia Lithium costs 2.8-5 Wh/US$ to buy, get 300 to 1200 cycles.
For the last time, we're *NOT* talking about traditional li-ion; we're talking about *variants* on li-ion chemistry, such as phosphates, titanates, and spinels in current gen batteries, and lithium vanadium oxide, tin nanoparticles, and silicon nanowires in next gen. How many times are you going to repeat this straw man? A123 rates their batteries for 10+ years, 7k+ cycles, and even then, you're only looking at 10-20% loss in charge capacity. LG Chem expects theirs to last for 40 years in typical use. These are more like Edison Cells in terms of reliability.
battery cost of lithium polymers
We're NOT talking about lithium polymer either! Cut with the straw men.
I am test engineer in charge of a 3000 Hp Hybrid vehicle prototype running some very hot Sodium batterys
Lol, zebras? Yeah, wake me up when you work with anything that'll ever be relevant.
and their energy density is actually greater than diesiel fuel per weight.
Not. Even. Close. 0.2 Trust me, I know their are no batterys available for purchase by any person, or a company for mass production that has energy density, cycle times and efficiency for a reasonable cost per Kw Hr
Oh, you're right. It's not like *Freaking Dewalt Power Tool Battery Packs* use A123 LiP batteries or anything. Or several other brands now. Or like they're becoming the defacto standard for hobby aircraft and helicopters. Or like virtually all new EVs and electric motorcycles from major companies are using them, or like most hybrids are switching over (a couple are still sticking with NiMH, but not many). Or like any of the following companies exist and produce these batteries: A123, AltairNano, Compact, Ener1, Hitachi, Johnson Controls, Lithium Tech, Maxwell, Automotive Energy, Panasonic, Valence, Toshiba. It's not like these batteries are powering vehicles like the Killacycle and Wrightspeed X1 that almost beat *gasoline vehicle performance records*
No, go live in your little fantasy world where none of this exists.
Sorry if I'm snapping at you, but I'm amazed that you're continuing a debate about something that you know absolutely nothing about.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
Corr: The line that starts "Not. Even. Close." should read:
"Not. Even. Close. 0.2 MJ/kg for Zebras (~90Wh/kg) < 42 MJ/kg for Diesel"
I don't mean to be too harsh on Zebras, but really, they're simply obsolete tech. A few companies still use them because they're "mature" (the prototype for the Smart EV, for example), but they have way too little power and the heating requirement is a waste and can be a pain in a number of situations. And they only last a few thousand cycles. They really have absolutely no advantages over LiP or any of the other long-life li-ion variants. And their obsolete nature shows; check out the reviews of the drive in the Smart EV. That's, what, 0-60 in "quite a while"?
Please, for the love of God, read up on the modern li-ion variants before you post again. Read up about lithium phosphates (in particular, lithium iron phosphate). Read up about the titanates. Read up about the spinels. Read up about the upcoming affordable BEV and PHEV lines from major manufacturers and new startups alike -- the Volt, the MiEV, the R1e, the Aptera, the VentureOne, the Loremo, and on and on. It's all variants on lithium ion, mostly LiP. Extreme charge effiency (~99.9%), very long life, safe, extreme power density, and while they don't have the energy density of their traditional li-ion bretheren (they're only ~100Wh/kg, although that's improving), their other qualities make them extremely attractive for automotive applications.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
Just as a follow up - AutoSpeed is running a great article on BSFC or Brake Specific Fuel Consumption.
AutoSpeed - Brake Specific Fuel Consumption
I highly recommend this to anyone interested in how different operating conditions affect fuel economy.
BSFC is the measurement of how much power vs how much fuel in consumed - basically measuring how efficient an engine is. In an ideal world you'd have an electronic throttle and a CVT. The throttle would directly translate into how much power you are requesting. The ECU would use a BSFC map to determine the most efficient engine RPM and throttle body position to generate that power and the CVT would allow you to maintain that RPM for as long as you are requesting that power level.
The displacement is just 2.5 liter, and as you guessed it, it's turbo'd. There are modifications to the intercooler and turbo, as well something you may consider cheating: the ability to select between three different modes that change the air/fuel ratio, the throttle mapping, even the assumed octane number. I am a lot more of a computer geek than a car geek. I spent a lot more time (but not money) playing with the chip, sensors, mappings, limit conditions and fuel ratios than with the true hardware mods.
:-)
The result is that my car can switch on the fly between fuel efficiency and performance. Also, with a fuel change (to 95+), a cold reset (so it forgets the months it's been running on crappy CA gas), and a switch to the third mode... lets say it does well enough to make me forget the money I burned and the warranty I voided
And the 38mpg is my absolute best - almost no city driving involved, and no traffic on the I5. In the city, I have a HARD time approaching 20mpg, with super conservative shifting. On the other hand, Vegas and back with three passengers and one tank of gas is not a problem.
(Yeah, the cold reset requirement is a disgrace that needs fixing. I'll get to it one day)
No good deed goes unpunished...
Thanks for the info guys -- but nothing I can go out and buy in my area yet. The smart EV is only available in Europe, but only as a trial, and not available to the public even there. That's the one that comes closest to what I had in mind -- it's even available as convertible, which is a plus. The range is a bit short, but probably usable. The price of the gas version is cheap enough, but they haven't said what the price of the electric is.
Computers obey me.
"I hope you like Guinness, Sir. I find it a refreshing substitute for, er... food." Col. Jack O'Neil, SG-1
My motorcycle has a flat torque curve from 4500 rpm to almost 10000 rpm. By any definition of the word torque, I have a lot of it.
By a qualitative definition where torque is a quality where an engine has "oomph" in a large portion or its rpm range, I have over 80% of peak torque available in 75% of the powerband. I ride a freakin' stump puller.
By a quantitative definition, my bike makes 125 ft-lbs of peak torque. Both for a 1.4 liter engine and for a 500 pound vehicle that is a heck of lot of torque. 6th gear tops out at 195mph, but I can drive around in 6th at 55mph and still pass cars with very quickly without shifting. Magazine tests list my bike with a 2.4 second 60mph to 80mph time in 6th gear when stock. Mine isn't stock any more, stock was 97 ft-lbs of torque.
I can do 0 to 60 in 2.7 seconds and 1/4 mile in 9.8 seconds at 150mph. I can also get 45mpg if I drive nice and well over 50mpg if I really try.
Just rub it in why don't you. You make me miss my old '85 CRX. I could actually get upwards of 34 mpg on the highway with my manual transmission.
If nothing else, the diesel hybrid is already available (not sure about the US)...which has fantastic milaege and still falls in at the very affordable rate.
I guess thats what separates you from me, I am working on this, your reading about it. I have tested examples of these in the real world, batteries manufactures are way optimistic (liars or damn liars come to mind.)
You have only read what people with no product to sell, claim they will have, or are developing, or maybe "are testing" at the best. A quote from Yogi Berra comes to mind "In theory there is no difference between theory and practice. In practice there is."
You're right. I've never used a dewalt power tool. I've never talked with people who use them in hobby aircraft building. And it's not like I've read half a dozen *peer reviewed* papers on the subject. No, live in your own little world.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!
Thanks for the correction
If I have been able to see further than others, it is because I bought a pair of binoculars.