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EPA Fuel Economy Myth: Too High, Too Low?
ThosLives asks: "I have seen here on Slashdot , and just about every other publication, numerous articles about fuel cells, hybrid vehicles, and the inaccuracies of EPA fuel economy stickers. For instance, today there is a review of the Toyota Prius that had the famous line 'Since no car really achieves the EPA estimated mileage...' I happen to drive a car with an EPA sticker of 21 city 25 highway (all figures in miles per gallon). I've driven the car for 47000 miles and the lowest I've ever seen is 23 and some change; the highest, 36.3 (I'm probably about 60% highway 40% stop-and-go and yes, the high was on a long highway trip). My all-time average is about 28.5. As most people get less than the EPA mileage, how does the Slashdot readership fare when it comes to EPA sticker vs actual experience, and on what type of vehicle?"
"Am I a rare breed that can drive my car (2.0L I4, 170 HP, 6-speed manual) aggressively (I've had coworkers and friends say 'woah!' more than I'd like to admit *grin*) and still stomp the EPA sticker? Did I get lucky with a phenomenal car? Am I enough of a counter-example to thwart the belief that the EPA figures are 'too liberal'? Are fuel economy issues just FUD from [insert lobby group of choice]? Or is the answer simply 'it depends on how you drive, what you had for breakfast, and the color of your neighbors' cat?'"
Your mileage may vary.
i drive a saab 900 SE turbo. mileage should be around 27 hwy, I generally get 27, and on long trips the computer reads 30+.
city gets lower than the 22 rating, around 18.
https://www.accountkiller.com/removal-requested
It's a company car with the 3.4 liter engine. I am a fairly assertive driver and put at least 25,000 miles a year on it. I've had 3 very similar cars over the last decade and consistantly get over 25 mpg in a mix of Interstate and light city driving. I think the operative phrase here is "Your mileage may vary".
For some reason I seem to get reasonable good mileage regardless of what I'm driving. At one time, years ago, I had a 1976 Mercury station wagon, totally a battleship with a 460 V-8 and managed to average 14 mpg with that boat hauling my 5 kids and wife. Again, I emphasize that I'm not an economy minded driver. I am a "Get from point A to point B" with a minimum of fuss and delay sort. I never get more than 10 mph over the posted limit, so I mostly go with the usual flow out here in the plaines. A little over a year ago I drove my mom's Buick to Arizona for her. It's got that nice 3.8 liter engine and is not a light car. I drove 1,750 miles in two days and got 28 mpg, but admittedly it's all Interstate driving, but out West traffic moves at 80+ mph. I was reall surprised. I've also driven some larger Chrysler products on long trips with mileages that were similar. I've concluded that modern cars do a pretty durn good job of fuel economy even in some of the larger configurations.
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
"Do the Right Thing. It will gratify some people and astound the rest." - Mark Twain
I'm a bit of a wonk when it comes to gas milage: I keep track of all of my gas purchases.
I used to have a standard 96 Ford Escort (no AC) that regularly got around 30-35 MPG in about a 60/40 Highway to "City" split. I can't remember what the EPA numbers were for that model, but I remember that I was around or slightly above them.
I now have a MINI Cooper S (fun f**king car). Under the same driving conditions I was getting about 23-24 MPG, which was lower than EPA. I have since moved and the drive is now 30/70 HW vs City and it has dropped to the 21-22 MPG range.
Car: Audi TT(6spd 225HP 1.8L turbocharged sports coupe). EPA: 20/28. Actual average for a tank has ranged from a low of 24mpg to a high of 33mpg. The 24mpg is a fairly even mix of city and highway driving. That value seems to correspond pretty closely to what one would expect from the EPA numbers. The 33mpg is all highway, of course, in sixth gear, with no turbo.
Of course, MPG greatly depends on how you drive, the state of the car, the fuel, the weather, traffic, and terrain.
The EPA numbers are a relative guide. They won't tell you exactly what you'll get for fuel consuption. However, you can easily use the EPA numbers to compare two cars' relative fuel efficiency. In fact, I submit that there is no better guide available for cars sold in the US.
I don't recall the EPA sticker figures on my car, but I have a '98 Saturn, and I get 31-35mpg.
Of course, I drive like a little old lady from Pasadena (not the one of the Beach Boys fame, though). I usually skip breakfast (perhaps it saves weight?), and my neighbors cats are grey...
"Time flies like an arrow, fruit flies like a banana" --Karl or Groucho, I forget...
http://www.fueleconomy.gov/
My mileage dropped drastically after pieces of the neighbors' cat got caught in the air intake.
If it hadn't been a black cat I wouldn't have run over it at night.
So, yes, mileage depends on the cat's color.
Show me on the doll where his noodly appendage touched you.
When the weather is warm, and that seems to be the biggest factor, I get the EPA-rated 70 mpg or more in my 2000 Honda Insight. 55 on cold winter days.
Driving at moderate speeds is also a big factor.
It's a travesty when a 3800-pound 2004 Pontiac GTO (classed as a compact car) that gets, in reality, about 20/26 is "rated" by the EPA at 15/18, and gets a $1000 "gas guzzler" tax...while the 8000-pound Ford Excursion in the next parking spot gets fuel mileage so bad that it isn't even rated...but is eligible for medium-duty-truck tax writeoffs, and no "guzzler" tax. The whole system should be dumped in favor of vehicle choice, not artificial limits put on cars by the government.
(I've had coworkers and friends say 'woah!' more than I'd like to admit *grin*)
Ye who speeds, cuts people off, and winds through traffic, is the first to reach the red light.
Candy-Coated Knowledge
I'd have to say that the biggest part of keeping my fuel economy up is keeping my car in good shape though. I had the muffler on my car die recently, the pipe basically decided to rust off the muffler body. I noticed a little bit of noise, but the pipe was still in the muffler and they were both connected to the car so nothing looked out of place. The big tip off that something was really wrong was the reduced fuel economy. Took it in to a trusted mechanic, got it fixed, and the mpg was back to where it should be.
Also, keep your tires inflated to where they should be. I'm told this is the best way to increase fuel economy.
If not now, when?
Similar for me. I only keep track of my mileage when I'm trips, but my 28 mpg highway rated sedan consistently gets over 30 mpg, and I've hit 33 mpg several times.
I've heard it said that a typical vehicle gets the best mileage at 55 mph, and that for every 5 mph above or below that, subtract 1 mpg. I'm an aggressive accelerator, but I rarely go much over the speed limit any more, so this might be where some of my luck comes from. In fact, the best mileage I've ever gotten was when following my father-in-law when he was driving a moving truck at about 55-60mph the entire stretch from Chicago to Kansas City.
Punctanym: alternate spelling of words using punctuation or numerals in place of some or all of its letters; see 'leet'
I've always get between 2-5 MPG less than the EPA ratings in my cars. I can get the EPA ratings, but only if I don't speed. None of this surprises me given how the tests are performed and what criteria they use for city (urban) and highway (extra-urban) loops.
:)]
Now what is interesting, but not really surprising, is I get the best gas mileage from my V8s. They work a lot less than the 6s and 4s I've had when you get on the highway [car body design is a great factory in this, obviously
I own a 2002 Toyota Prius. Just rolled 50,000 miles tonight. Highest tank MPG was 62. Rock bottom worst was 45 MPG. Normal commuting mileage is 57-58 (without A/C), 52-53 with A/C.
Driving habbits matter. My wife (lead foot, middle name of "Never Say Brake") gets a good 10 points worse than I. Short hops in city/suburb traffic will lower the gas mileage down to the low 40's. Careful use with highway/rush hour traffic will push it toward 60.
It is like anything else. Your mileage may vary, but for me, the government underestimated the mileage.
how loaded your car is, how much you drive up hill, how often you brake or decelerate, now hard you accelerate, which way and how hard the wind is blowing (literally), how bald your tires are and whether they are aligned, is it a hot day, cold day...the list goes on.
seriously there are tons of physical factors that will affect your mileage. The EPA estimates are just that - estimates. Values that are in the ballpark of what you can expect to get.
Is the juice worth the sqeeze?
The car should be within the range of city to highway. If it isn't in there, then you should demand your money back.
I don't think that is that simple. The EPA tests are standardized, and I bet that if you drive in a manner, place and weather that the EPA tests use, you'd probably get those numbers. Drive in snow, rain, cold, heat (with A/C on) you might see something different. This is exactly why people say that benchmarks don't tell the whole story, the tests to arrive at the figures registered by the EPA is a benchmark, no more, no less.
My previous car was a '93 Ford Probe. It consistantly beat the EPA fuel mileage estimates by about 3-5 MPG My current car is an '02 Dodge Neon. It's consistantly worse than the EPA estimates by about 3-5 MPG.
Reading some of the other posts, it seems that older cars beat the EPA mileage and newer cars do not. Is it possible that the EPA changed their methods for estimating mileage?
Side note: I sure miss my '93 Probe. Sniff.
Key to financial independence: Spend less than you earn. Save and invest the difference. Do it for a long time.
It had to be said...
I think, therefore I thought.
Auto manufacturers are required by EPA (environmental protection agency) mandate to post a car's estimated city and highway fuel economy on the price sticker for new cars.
The slashdot readership has probably faired the same since this story originally ran. Oh, wait.
Yeah, right.
I ride a Honda 500 cc motorcycle and get 50~70 mpg depending on how I ride it. The only trade off is that I put better quality gas in it because its engine runs a hell of a lot better on premium gasoline. People should really look into two wheeled transportation as it's fun to ride and a lot more economical than the vast majority of cars.
Cars, like anything (say computers) are best at what they are designed to be best at. Just as Intel processors are very good at things that can be pipelined and demand high throughput, Via processors are very good at using low power and a small footprint. If you try using the device for something it wasn't OPTIMIZED for it will not perform - regardless of how great it can do what it is really meant to do.
If you look at Prius (and hybrid designs in general) they are based on city based use cases. Shut off the engine at the stop light & fuel economy goes up. These same cars on the highway won't perform as well. As to the 'Highway' and 'City' designations - these should be used a general baseline, not the rule.
I have personally found that some cars do better than their EPA while others don't. Lots of factors weigh in... age of the car, using the correct octane gasoline, how well you keep the car maintained, if you cary around 150 lbs of crap in your trunk, the kind of tires you use, is the car in alignment, and the list goes on.
The truth of the matter is that if you have the same circumstances that the EPA had when it tested the car, you can expect around those result.
As a prior poster put it:
Your mileage may vary.
The whole system should be dumped in favor of vehicle choice, not artificial limits put on cars by the government.
The truck exemptions (that allow for SUVs to have pretty much any fuel economy [or lack there of]) came from the late 1970s when most trucks were used by farmer and construction workers. The idea was to help those people, who generally are involved in small business and make peanuts anyway.
Times have changed, now everybody and his brother has an SUV or pickup truck (even if they don't admit it). The regulations haven't changed, not because of a scam, but because the federal beaurocracy is a mess. Sure, the oil-loving administration isn't going to hurry along any changes, but they aren't doing anything actively to prevent such changes either.
Sounds like he has a Ford Focus SVT, just in case anyone was wondering.
"In a cat's eye, all things belong to cats."
An EPA sticker is the printed result attached to each new car that reports the result of an EPA established test that gives estimated fuel mileage, both city and highway.
The test is completely artificial, being run on a dynomometer (no hills, wind, weight in the trunk, etc.) but has the considerable advantage of no being subject to these same variables when the test is run.
EPA established this test for emissions testing, but the government has made the results of this artificial test both required and the only allowed gas mileage estimate car manufacturers are allowed to post on the new cars.
Good -- consistent, easily compared, verifiable
Bad -- not representative of actual usage. Misunderstood by many consumers.
My '03 Hybrid Civic had (I think) 48/47 on the sticker. When I drive it, the "MPG" meter in the dashboard ends up around 42-46. At the pump, I actually get 39-44.
-- I prefer the term "karma escort."
You Americans could learn a lot from the rest of the world when it comes to getting more MPGs.
:-)
Just do what we do -- use a bigger gallon!
Low-tech solutions to hi-tech problems
Or perhaps the last to make the green (or yellow)....
May such a driver be ever cursed with poor cellphone reception and the cold dregs of yesterday's Tarbucks beverage spilt on their lap.
Toyota doesn't mess around. They've also sold the hybrid technology to ford. Let's not forget that toyota is also releasing a hybrid which does 0-60 in 4.03 seconds and tops out around 155mph. Don't walk away from this thinking Toyota is maniacally evil, if anything, they've got their shit together more than most automotive companies.
Sorry for being a toyhead, they please me immensely. Something tells me, if the author of the article was driving a volta, miles per gallon would be the least of his worries. I think toyota pretty much tops the list of fuel economy, on any playing field. Prius wins in my mind, not strictly because of fuel consumption, but by the name that's behind it.
In cold weather the Prius got between 35-40. Now that the weather is nice, I've been getting 48-52 for my commute. My wife who does more short trips and sits at lights with the AC on gets quite a bit less. The first 5 minutes in the Prius is very poor (about 25) as it is agressive in maintaining the engine coolant temprature for the low emissions. If it was designed for millage instead of emissions, it could do a lot better. Where the car does a fantastic job is in stop and crawl driving if you are not using the AC. It does that with the engine off 90% of the time. Conventional cars don't fare nearly as well as you are stopped too short to shut off the engine and sitting idling is zero MPG. An extra bonus is the car doesn't overheat in those conditions like my old car did. A warm day and stop and crawl traffic would usualy result in some loss of coolant.
The truth shall set you free!
The EPA estimate is based on the emissions of the vehicle. Recent cars have a number of additions which reduce emissions, but don't affect mileage.
Call it optimizing for the benchmark.
This is not a political statement. This is not legal advice. It's a frick'n Slasdot post. However: I'm Running For
I drive a 2000 Jetta TDI, and I am no light foot with it. The EPA rating for the car is 42/48 and my personal lifetime average for the car is currently at 47.1 MPG. On longer trips of predominately highway i have had mileage about around 52-53 miles per gallon, this is with cruising at 70 mph. Got to love driving a diesel car :)
This frustrated the hell out of me for a really long time. Then I inflated the tires all the way to near their "max pressure" rating and suddenly my milage is way better than before.
So yeah, I'm a moron for not checking this sooner, but JFC, you'd expect them to properly inflate the tires when they install them!
This does bring up a question though: should tires be inflated to their stated maximum, or below that? If so, how far?
(this assumes cold tires)
Dude, I think I can see my house from here.
While it is true that with age a cars mileage will tend to get worse due to carbon build up, what really effects your mileage is the quality of fuel that you use!! The higher the octane does not matter, but which brand most definitely does. For instance, at the risk of sounding like a corporate sponsor, Shell gas on average gives me about 30-40 more miles per tank than most gas.
They also depend on what gas you put in the car. Some cars do drive better on supreme.
When I used to live about 400km from my hometown, I spent the first while driving home on regular, it took about half a tank to get there (45L tank?)
However, when on a whim I tried "Supreme," it actually took me just a little over a quarter... so milage and bang-for-my-buck was actually better on the more expensive gas. Possibly this also has to do with the mountainous terrain and the fact that the gas gave me more power - not sure.
I do know that I regularly stick injector-cleaner in, so I shouldn't be getting plugged there. Therefore, I'm willing to state that better gas can give you better milage (and not all gas stations give the same quality gas either)
"Why does it "seem" to be really important to know this in the US, and completely irrelevant here in Aus ?"
Fallout from the gas crisis of the 70s - our government has mandated that cars produce certain mpg or they get hit with a "gas guzzler" tax, which tops out around $4000 for the biggest drinkers - Vipers, Lamborghinis, etc.
Also the mpg is on the sticker as a shopping guide for comparison purposes for those who care about such things. Exempt from this are large trucks/suvs, which of course get the worst milage and don't pay a gas guzzler tax.
The first thing we do, let's kill all the lawyers. Shakespeare, Henry VI, Part 2, Act 4, Scene 2
My 90 ZR-1 was stickered at 16/25. I got 18 city, and from 27 (80mph) to 33 (65mph). Not too shabby for 375 hp.
:)
Its replacement, a 2004 Z06, is stickered at 19/28 and I'm seeing 18.5/33-35 quite respectable and 405 hp to boot.
I love it when some econo-box criticizes my sports car as a gas guzzler and finds out I get better milage than they are
The first thing we do, let's kill all the lawyers. Shakespeare, Henry VI, Part 2, Act 4, Scene 2
My diesel 2001 Jetta TDI gets about 54 MPG for highway driving (doing 75+ MPH), and about 48 MPG in the city. It has 90,000+ miles on it, and still drives like a champ. Plus, diesel prices fluctuate less than gas does.
r g/
Before people start to complain about environmental concerns, do the research first.
http://www.tdiclub.com/
http://www.biodiesel.o
I did a lot of research when I bought, due to my long commutes (150+ miles/day), and I save, on average, between $250 - $300 per month, which essentially paid for the monthly payments.
Great car. They also have Diesel Golf, Beetle, and Passat models, if the Jetta doesn't float your boat. Worried about not being able to find diesel? When my low fuel light comes on, I still have a 2 gallon reserve, or about 80 miles in the city, but in reality, it's not that difficult to find diesel.
They're definitely worth checking out. I plan on being able to keep the car for a number of years, as the engines last forever. Sorry to sound like a diesel advocate, but it's a great, comfortable car.
Any one of these can swing fuel consumption. Driving my Jeep like a granny, shifting once I hit 1,500 rpm (not a problem since it has so much torque) gets me close to 18 or 20 mpg, even with big tires. If I drive around like "normal" people I'd be getting closer to 11 or 12 mpg in the city.
However, having lived in a suburb where I would have to drive 45 miles a day just for work, to now driving less than 5 miles/day if at all has meant that by moving to "the city" I have reduced my personal emissions/day tremendously.
One interesting to note about tire pressure. I left San Francisco (65 degrees) and pumped the tires to 33psi cold. By the time I got down to Fresno it was getting a bit squirrely. When I checked the pressure it had hit 40psi! I let it back down to 32psi and continued onward. Coming down the 10 heading into Phoenix it felt weird again. Lo and behold, the 115 degree ambient temp had pushed the pressure back up to 38.
The point being that you need to keep your tires inflated to the pressure that gives you the lowest rolling resistance. I'll be changing out the 33x12.5 to 33x9.5 tires.
Keeping the car well maintained is also a bonus.
and measure the difference in your mileage. I've got a '01 Explorer V8 AWD, which I usually drive like a bat out of hell getting 18.5 mpg commuting with about 70% Hwy miles. As a test, for an entire tank of gas, I drove like a wuss, like there was a quail egg between my foot and the accelerator, never more than 2K rpm. This meant very gentle starts, keeping top speed down to 65, and leaving lots of room in front so you have to brake less, driving in the right hand lane, and allowing lots of folks to speed past. Results: 21 mpg, a 13% increase, saving about $4 a tank @ $2/gal. Psychologically, it was pretty peaceful driving that way and it didn't take that much longer to get there, so now I routinely drive in a kind of half-wuss mode and I'm getting 20 mpg, mainly because its less stressful. I think this car is EPA rated for 19 Hwy.
Hybrids are interesting, but the economics are not there yet. I calculate that if a Hybrid Civic (epa 51 mpg) costs $4900 more (after rebates & incentives) than a standard Civic (epa 38 mpg) and gas is $2.10/gal, you'd have to drive it over 300K miles to break even. Anybody who is buying these cars deserves an attaboy for being a brave pioneer and donor to developing technology.
it's the 90CS Quattro Sport, 5 speed. The car itself weights just shy of 3500 lbs, and then there's occupants. I'm still amazed at how agile it is with all that weight being pulled around by a 2.8L engine. The AudiWorld page for my particular car says 19mpg city, 24mpg highway but I can get closer to 30 in the city if I manage to not do craziness around town. I tend to shift at lower RPM's, I catch some flak for it but I go to the gas pump half as much as they do.
Everyone that's driven this car is very surprised because it doesn't look like much but it can handle the rice boys fine. If it's in anything except clear conditions, don't even try. You've never lived till you spin all 4 wheels on gravel or ice while it gets grip. I can't imagine what putting a supercharger on there will do. I've had the car for over 2 years and I still get goosebumps from the performance.
The EPA gas rating is a Federal Govt issue, but many states have different gas blends, and sometimes different blends at different times of the year to meet air quality standards. Here in California, there's ethanol and other oxygenates in the gas. The sum total of which, reduces the amount of real combustible gas per gallon, and so reduces the MPG. So, it matters what color the neighbors cat is, what month it is, and where you buy your gas.
The reason most people don't get the advertised mileage is because they goose it at most every opportunity and race up to the light and then get on the brakes. More sensible driving patterns will get better mileage. I like the hybrid cars because they provide real time feedback both in text and graphics as to your mileage and fuel consumption. I wish conventional cars would do this also.
I'm riding a Honda Rebel around town now. The car I replaced with the bike was a 1992 Toyota Corolla that pegged in at about 30 MPG on the highway and 21 on the city streets. Since most of my driving was city streets, I'd have to fill up every week or less, depending on the travel schedule. The cost of gasoline now would make my average trip to the station about cost between $25 and $50 per week, again depending on how many times I needed more gas.
I've had the bike for about 2 months now, and I think I reached $50 total in gas this weekend. I haven't figured out the total mileage yet; when the tripmeter reaches 150 miles, I get paranoid that I'll have to cut in the reserve (2.1 gallons in the primary, .6 in the reserve) so I fill up. I always go in and put $5 on the counter, fill up the bike, and go back and get my change. I'm guessing that I'm hovering around 80 MPG.
And I'm getting a tan while I run errands.
There's so little difference between politics and jihad lately...
My preferred method of transportation gets 1.2 gallons per mile....
Which is better than a hybrid car for certain numbers of people.....
Fellowship 9/11
All these SUVs are beginning to embarrass me. Everybody knows that reason that people buy them is because:
1) They get '$4000 cash back'. Or something like that and they need the money.
2) 'No interest and no payments until 2006!' Or some other absurd offer like that.
3) 'Just show your paycheck stub to trade in your current rust bucket and drive away in a giant houseboat on wheels for $100 down'.
4) You can write off the entire cost of the vehicle as a tax deduction. This got slipped in the middle of one of those 1000 page Defense budget appropriations bills years ago.
What is really getting to me about these people who drive around (alone) in these HUGE vehicles is that they have no sense of public shame. Everybody knows that American solders are getting killed in the Gulf daily to protect the oil supplies, so these assholes blatently drive around in a car that gets 10 miles per gallon (roughly 4 km per liter) and then they put some flag decal on their back window to show how much they support 'our boys'. If they really cared about whether or not the solders were getting killed then they would be driving a car that gets 30 MPG and there wouldn't be any need to send 130000 solders to the Gulf to ensure the oil supplies.
Everybody knows this. But all SUV drivers just don't give a fuck. And they seem so overjoyed to stick their HUGE vehicle in everybody's face to remind people that they either don't care or they're just too stupid to make the connection.
Everybody knows by now that the giant SUVs are just given away as tax write-offs. Myself, I would be ashamed to drive around in one of those because everybody would know that I cheated the taxpayers through a bogus tax-write off to get one. But they, the SUV drivers, just don't have any sense of public shame. They must think that the rest of us are happy to see them coming down the street in giant houseboat on wheels.
We're not. We're embarrassed by you. You make us look bad to the rest of the world. Everybody in the world looks at Americans now and says 'How can these people be so vulgar and stupid and have so much money?'. It's not a situation that has any real long term growth potential or stability. Then they start to analyse the situation and realize that the whole US economy is held up by the willingness of foreign parties to buy US government Treasury Securities to support the giant US government deficits and by the willingness of foreign parties to use the US dollar as a defacto global currency. So when the Chinese (who finance most of the US federal government deficits by buying Treasury bills) start buying the oil that they need directly from OPEC through private deals (not on the open market) and paying for it in Euros, the Americans are going to be in a bad situation. Because no one will need them or their bullshit anymore.
A lot of these SUV owners don't seem to realise that this giant piece of shit that they're aiming down the road is in all likelyhood the last new car that they are going to own. And, if things get real bad, they may find themselves living in it. That's their retirement housing: a Ford Expedition sitting on cinder blocks with the seats torn out and Winnie-the-Poo curtains on the windows. Renting a 5x5 meter plot in a trailer park built on a depleted Uranium dump site for $3000 a month.
Altough, around 2 months ago I performed a 'test'.
During the whole tank of gas, I accelerated as slow as I could never pressing the gas more than 1/4 of the way. I knew the lighs were going to turn red, so why accelerate? I eased on slowly and came up to the red using as little break as possible (a waste of energy)... maybe even rolling into the light as it would turn green and _then_ slowly accerlerating.
On the highway, I would stay in the right lane (insane for me). The speed limit is 70, but I would hold 63.
For the tank I averaged 35mpg.
Moral of the story. The car you choose does have a lot to do with your final MPG. But your driving habits also have a huge amount to do with your fuel usage.
1. Check your tire pressure at least once per week, preferably before you drive the car for the day. If the tires are properly inflated, you get lower rolling resistance, which can improve fuel efficiency as much as four percent.
2. Change the air filter once every three months. With a clean air filter, you get better engine breathing, which can improve fuel efficiency several precent.
3. Keep the fuel-delivery system clean. That means you should run something like Chevron's Techron additive to your fuel about three times per year to keep the fuel injectors clean. Also, consider having the fuel injectors removed and cleaned manually by a good auto repair shop every 36,000-40,000 miles or so. A dirty, potentially-clogging fuel injector can not only hurt fuel efficiency, it also hurts overall engine performance, too.
4. Replace the spark plugs at slightly shorter than manufacturer-recommended intervals. An improperly-working or worn spark plug can hurt fuel efficiency and overall engine performance quite a bit.
5. Don't drive too fast. Keeping the speed under 75 mph usually helps fuel efficiency since you're dealing with less air resistance when running at lower speeds.
6. Keep the windows closed on a sedan or coupe type vehicle if you're travelling above 40 mph. An open window causes considerable air resistance at higher speeds, so much so that you actually use less fuel with the windows closed and the air conditioner running than having the windows open when you're driving on the freeway.
Look in the door jam, glove box or on the back of one of the sun visors for the manufacturers' recommended tire pressure. Usually around 30-34 psi. Don't go by "max pressure" on the sidewall of the tire.
Nope. Use the max pressure on the sidewall of the tire. The places you've suggested will speak *only* of the tires that were installed on the car by the manufacturer. Worse yet, some cars will put low numbers like 22psi or less, to give you a smoother ride, and eat up your gas mileage like there's no tomorrow.
Using the number on the sidewall of the tire you're guaranteed to always have less than the maximum pressure the tire is rated for. Why? You may ask.
I will tell. ;) The max pressure rating is for cold tires with cold air. Unless you're like me and you happen to have an air compressor in your driveway, you'll have to drive to a place to get your tires checked, and they'll be hot (or at least hotter than cold).
The only catch is, if you live in a place that actually has seasons (so, nowhere in the southwest or the south) then you'll need to check your tires at least once a week starting in the springtime and heading into early summer. Then you can drop back to once a month again. The higher summer temperatures could cause any extra air you have from adding air in the wintertime to expand enough to push your tires beyond the max rating, although it's unlikely to pop them.
Most tires will still go another 14-18psi over the max rating with no trouble, albeit with a noticeable loss of traction. Whenever I take a trip I usually throw 5 more pounds in my tires to get better mileage on the highway (the longer the trip the more I worry about it, that stuff will add up over the length of the trip, and if I can have another $20 at the end of the trip not spent on gas that means I can buy more soda for the ride back ;) )
But when it comes right down to it, the only reliable spec you have for the tire you're filling is the spec moulded into the tire. All other specs are unreliable because there's no way to verify that they refer to exactly your tire.
Like what I said? You might like my music
I get twenty kilometers per litre, that's about fifty miles per gallon, on average, and that's with a very ordinary turbodiesel, nothing fancy or especially fuel economic (and a pretty quick driving style).
Well, you've got two different replies, and two different answers.
One says: Use the number on your doorjamb or glovebox, the other says to use the maximum on the sidewall.
I say: Something in between!
For example with my WRX, the max on the sidewall of the RE-92s is 44psi. The recommended pressure from Subaru is 32psi.
It is a well known that running at the manufacturer's recommended pressure is designed to give a nice smooth ride and still be high enough to lose a bit of pressure and not have to worry about overheating the tire on the freeway.
Similarly, the tire manufacturer is going to design some amount of error into the maximum pressure that the tire can hold to account for in-accurate gauges and temperature changes. I have heard that the tires can hold over 90psi without blowing up, so you should have plenty of headroom.
However, what does happen at higher PSI ranges is that the tire will start to balloon, and you will find that the center of the tire will wear faster than the edges. At this point you will also start to lose traction. You will get better gas mileage, though!
I have found that in general running somewhere around 2/3's of the way between the car manufacturers recommended pressure and the tire manufacturers maximum pressure seems to be a good compromise between comfort, even tire wear and gas mileage. You should also experience an increase in overall traction and more even tire wear if you corner agressively as the lower pressure settings allow for excess flex in the sidewall loading up the outside edge of the tire. For me this means running about 40psi. I also like to run 1-2 psi lower in the rear, to account for the fact that in general there is less weight being carries by the rear tires, so this gets you a more consistent contact patch from front to rear of the car.
Of course, YMMV, and you may want to adjust your tire pressures to your vehicle, tires, driving style and road conditions.
People, people, people! Turbochargers are ALWAYS spinning, and ALWAYS moving air. Period! Its a closed system, and the only way around it is via the wastegate which is shut until you reach maximum boost.
:D
Of course, at low rpms the effect isn't very noticible because you'll still be generating an intake vacuum - only it'll be slightly less than a naturally aspirated car. Now it depends on the turbo and what its compressor map looks like, but even a little gas (like when cruising) will spin the turbo fast enough to significantly cut down on intake vacuum. Get on the gas a little though, and you should see the vacuum decrease to the point of equilibrium, where the turbocharger is compressing air approximately as fast as the engine could suck it in by itself. Up to and including that point, its relatively easy for a turbo to move air because theres very little resistance. Above and beyond that though, you start generating positive pressure (boost), which is where the real work begins, drivers start having fun, and the fuel economy goes to shit. But nomatter what the engine is doing, the turbocharger is always doing its job, or at least trying to. Even at very low engine RPMs, your turbo can still be spinning at 10,000+ rpm, which is gonna move a little air no matter how you slice it.
So yes, parent is right. Turbocharged cars are always turbocharged. Its a common mistake to assume that your turbo isn't doing any work until it starts to generate positive pressure (boost).
Now get out there and enjoy the power-snails people!
not only are SUVs more dangerous to other drivers, they are a LOT more dangerouss to pedestrians and cyclists. normal cars are designed to minimize damage caused to a person. an SUV is not.
No one can understand the truth until he drinks of coffee's frothy goodness.
--Sheikh Abd-Al-Kadir, 1587
What you have to ask yourself, is why the govenrment are litterally pushing people to buy SUV's. Easy enough to try and build up the plausability for expending living people to protect, not oil (as how can you class it as protecting, when you are taking it?) but the interests of the oil companies.
I think an invenstigation needs to go underway, it is, or should be, illegal for this kind of law to be put in place.
I am shocked that this hasn't been a source of massive outcry, and protest, but hey, you don't want to be anti-patriotic.
Thanks for posting this, the fact that it hasn't been modded up, and the only AC reply is you are jealous of car sizes, shows what kind of a sick and twisted world this is!
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You got me interested. Care to share a few tips with the
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The end of oil reserves are only within clear sight if you intend living over 100 years (at current usage). What is in sight is the end of CHEAP oil. There will always be quite a lot of oil for our lifetimes and at least the next generation, but I expect we'll see the cheap oil gone fairly soon.
The economics of that will mean it begins more economical to use alternative fuels (biodiesels etc.) than dino-oil, and necessity will force the change. The websites about how society is going to collapse is the real FUD.
Oolite: Elite-like game. For Mac, Linux and Windows
A friend just had a Prius as a loaner, and another friend just bought the Honda Civic hybrid.
Being new and eco-geeky, both cars have extra instrumentation to let you know how/what the hybrid gear is doing, including instantaneous mpg readings. I haven't talked with the friend with the Civic since shortly after she bought it, but the friend with the Prius mentioned that the readings on the mgp meter tended to modify his driving habits. I wonder how much mileage on regular cars could be improved just by this type of feedback.
As a counter-example, back in the late 70's a college friend's Chrysler had a simple form of this - a yellow light that would come on when you were driving 'too aggressively' for good mileage. So of course there were efforts to keep the light on as much as possible.
The living have better things to do than to continue hating the dead.
My wife and & I "share" our cars... which arises from the fact that we only have one child seat. So whoever has our son at the moment, gets our Toyota Sienna, and whoever doesn't, gets our Toyata Camry. Both of these vehicles have a 1MZFE toyata v6, the sienna with the vvti head and the camry without, which translates into a modest HP increase for the sienna (about 25hp) the torque ratings are the same. The sienna is about 300 lb heavier than the camry. Both have automatics, and I believe both are EPA rated 19/26.
:) People here in Atlanta seem to treat the roads as a raceway... average freeway speeds are probably up around 75-80MPH even where the legal limit is 55MPH. That's gotta have an effect.
I've always tracked my mileage by going from full tank to full tank, but lately I found a palm app called "Fuel Log" (Open Source Free SW = cool) and have been using this for the last several months to track our milage.
This is where things get odd... The sienna over the same city/suburban driving routes with the same driver consistently gets better gas milage than the camry, like 21 vs 19. But on the highway, the camry does better, usually around 27, vs 24-26 for the sienna. When I drive a specific car it always gets better gas milage than when my wife drives it. I tend to drive harder than my wife does... go figure
Our previous vehicles usually did much better than EPA ratings. My old Escort GT was rated 25/30 I believe, and I never once got below 30, usually averaged around 32, and got as high as 35 on a couple of long hwy trips. My wife's old Mercury Tracer would consistently beat it's 29/35 EPA rating, and on a couple of long trips even topped 40mpg... Our even more previous car (94 honda accord) was much the same way.
Leads me to wonder if Toyotas simply don't match well to the EPA test. Who does these tests anyway? The manufacturer or the EPA or some 3rd party? Anybody Know???
Keep in mind that EPA cycles probably make the assumption that you stick to the speed limits
But seriously, we have urban, extra-urban and "combined" mpg. I find that I get almost exactly the "combined" mpg from a car once it's been run in, and I don't do many long trips. On long trips the mpg is quite close to the extra-urban rating. The EU measurements are actually very good compared to the pointless "constant 30mph/constant 56mph/constant 70mph" figures that were used in Britain until about 10 years ago.
When I am king, you will be first against the wall.
In case anyone thinks spineboy isn't being honest...
I've got a VW Jetta TDI and I consistantly get > 50 MPG (average about 52 MPG) in mostly highway driving. Also, around here diesel is 20 cents cheaper than regular.
Waltz, nymph, for quick jigs vex Bud.
I've found that my wife's car, a 2001 Oldsmobile Alero, while having many electrical problems, does in fact fall into it's EPA of 21-27mpg. It sits right around the low 20's usually, in mixed city/highway driving. My car, a 1964 Dodge sedan with a big block 318, gets about 25mpg in the same driving conditions. It doesn't have an EPA rating, but the manual claims it has 'nickel-squeezing gas economy' and an 'eager engine with lots of go', and it is pretty decent for an older car. Now how an Alero with a 2 liter 4 cylinder engine gets worse mileage than a 40 year old 5.2 liter V8, I have yet to figure out.
- True and relevant. The USA's import situation is directly affected by the difference between production and consumption; reducing consumption cuts imports just as directly as increased production does.
- Perhaps true, but irrelevant. Oil is fungible, and while Persian Gulf oil goes primarily to Europe and the Far East it would be simple to re-route the tankers so that all of US imports came from there... or none of them. This would have no effect on US import dependence, the political implications of e.g. Wahhabi financing of hate teaching, or anything else of importance.
- Perhaps true, but equally irrelevant for the reasons stated above.
Roughly half of all US oil consumption goes for motor gasoline, while over half of all US oil consumption is from imports. You could make every passenger car in the USA run on electricity and you would still not eliminate oil imports (though you'd probably collapse the world market for oil for a while and bankrupt a kingdom or three).Time is Nature's way of keeping everything from happening at once... the bitch.
1 Highway
0 City
...at least for GM vehicles. I used to work at a Chevy dealership. Occasionally someone would bring their vehicle in *insisting* that the mileage sucked and they couldn't be reasoned with. The customers method was usually recording the mileage and gallons at each fillup and doing whatever magic math they deemed correct to come up with mpg numbers. Oh, yeah, and most of the time it was a manual shift vehicle.
We had a locally built rig to use to check the mileage. It was a 1 gallon container, an electric fuel pump, a pressure line and a return line. We would connect it up to the vehicle, start it, and run it out of fuel to start the fuel system completely empty. Then we would put exactly 1 gallon of gas in the container, record the mileage on the vehicle,as well as the mileage on the chase car (to verify the odometer was correct) and both cars would take off. We made sure to drive the car easy without being a grandma driver, no hotrodding or heavy acceleration. Simply going with the slower flow and keeping within the speed limits. We would drive until the car drained the gallon container. Then we pulled onto the shoulder and compared miles traveled.
The route was planned to include a mix of city and highway driving in hopes we would end up with miles traveled in between the 2 advertised numbers. The route included about 6 miles of in town traffic, with at least 3-10 stops, depending on the lights and traffic, and 5-20 mile stretches of open highway in between.
We performed this task no less than 10 times during my 7 year stint at the dealership and the results were fairly conclusive. It beat the advertised highway mileage *every single time*.
(Stolen sig) Remember: it's a "Microsoft virus", not an "email virus", a "Microsoft worm", not a "computer worm
In Finland we have SUBSTANTIAL Gas tax. That means MPG has real result in my pocket. /gallon. Most of it taxes.
BAD MPG is from 70's soviet union made vehicles which is about 30 MPG and modern cars get around 60-70MPG. We pay 1.2 Eur/litre =~ 5.67$
If US would get anyway near similar TAX on gasoline [Passed with reduction of other taxes] Your thinkin 30MPG is good fuel economy would change. Also that would bring small shops closer to places where people live in order to reduce driving.
Emacs is good operating system, but it has one flaw: Its text editor could be better.
This is due to design decisions on the part of the auto makers: the hydraulic torque converter is a huge energy sink. If they used CVTs or a hybrid with a generator between the engine and transmission input shaft (turning the RPM difference of the slippage into electricity instead of converting it to heat) the difference would be a lot smaller, perhaps even negative.
Time is Nature's way of keeping everything from happening at once... the bitch.
I have to disagree. We do *not* need large, gas-hog engines for trucks and heavy equipment. I know of *no* heavy equipment that runs on gasoline today (they're all diesels, or for the really big stuff, diesel/electric). Big gas trucks are inexcusable. An F-350 SuperDuty with the PowerStroke diesel will get 17-19 mpg while doing 70mph towing 4000 lbs through a hilly area (and have enough power that you don't know the trailer's even there). Conversely, an *empty* same truck with the gas V10 will get no better than 10-14 mpg. Point being, diesels make more power with much better fuel economy.
You may call me a troll for saying so, but if you (the universal you, not the specific you) buy a big truck/suv and get a gas motor, you're a total idiot.
The Sacred Chao says, "MU".
Driving styles totally impact the mileage with hybrids. We have the Honda Civic Hybrid and when I drive I get about 41-44 MPG with combined highway and city driving. We live in a very hilly area, so we probably tax the gas engine quite a bit compared to if we lived in a relatively flat area.
When my wife drives, she gets about 38 miles per gallon consistently. The strange part is that I drive faster than she does. However, I think I "optimize" for the hybrid more. I ensure that I roll as much as possible with the engine off, I take off slower from stops (usually), and I try to keep the engine RPM below a certain level.
We also noticed that if you accidentally un-seat the gas cap a bit you can get better mileage. Something about the fuel pressure putting less fuel in the engine. It was good for about 3-4 more MPG.
TTFN
Yes, turbo diesel cars get incredible mileage, but the particulate emissions -- despite dramatic improvements over the past decade -- still fall near the bottom of the heap.
So, if you want to improve your mileage to save a couple of hundred dollars a year and/or to reduce dependance on foreign oil, a diesel is definitely the car for you.
On the other hand, if you're concerned about that grey haze hanging low in the sky that you notice every morning driving to work and wonder about what it's doing to your lungs, you might want to consider other technologies.
The point is that we reduce the dependency of the US on the middle east. The middle east has the US by the balls, and we've seen how they can be fickle with their fortunes. They'll cut production to raise prices, and then they'll increase it again once we complain a lot, but just a little bit. We're better off getting all of our oil from countries closer to here who are a bit more friendly to us. Also, the site had an interesting quote - "I don't think there's any question if broccoli were the number one export from the Middle East, we would not have gone to war in Iraq". You have to think that if there wasn't any economic benefit to those in power, would we have gone to war? I don't see us trying to liberate any of the african dictatorships.