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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."
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
What's the conversion so that solar cars can get "MPG" of gasoline?
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
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'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 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
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!
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.