I have seen comments about why European models

[melm00se]

get better gas mileage than some of the same US models.

I came across this in the paper over the weekend:

Dear Tom and Ray:

Can you explain why equivalent cars sold in Europe get much better fuel economy, compared with those sold in the U.S.? As an example, I was looking -- I suppose out of boredom -- at the Honda U.K. Web site. It shows the mileage for the Honda Jazz (which is called the Honda Fit here) at around 50 mpg, just as is, off the showroom floor. It's not a hybrid version, just the regular car! The equivalent base model in the U.S. comes in somewhere in the 30s for mpg. What's up? And yes, I know that an Imperial gallon is slightly bigger than a U.S. gallon. But the 10 percent difference in volume alone cannot explain the discrepancy in mileage. -- Lawrence

Beat up old carTOM: Boy, you WERE bored, Lawrence!

RAY: There are several factors at work here. The first is, as you mention, the Imperial gallon. The British use a gallon that is 20 percent larger than a U.S. gallon, not 10 percent larger. So right there, you increase the mileage rating by 20 percent.

TOM: The second factor is engine size. The base model Fit in the U.S. comes with a 1.5-liter engine. Because Europeans prize fuel economy over power, the base model Fit/Jazz in Europe comes with a 1.2-liter engine. That's true of a lot of cars sold in Europe. They often have smaller engine options not offered here.

RAY: And the third factor is the testing. The EPA mileage tests here in the United States are more realistic. They were changed a few years ago to factor in things that real drivers do -- like accelerate and turn on their air conditioners. European mileage tests are still less reflective of real-world driving.

TOM: Add it all up, and the same car can get a combined rating of 53 miles per gallon across the pond, and 31 over here.

RAY: Hey, if we send my brother over there, would his IQ rating be higher?

courtesy of http://www.cartalk.com/content/columns/latest.html

[Aviation Pro]

1. Desiel engines are mor efficient

.....

[Locrian]

2. hmm

>>Add it all up, and the same car can get a combined rating of 53 miles per gallon across the pond, and 31 over here.

Not sure I buy that - I believe the lower engine size is a big part of that difference. Yes, the testing and gallon size, etc - but not the SAME car 30 vs 50.

[melm00se]

6. OK, taking that into account (and removing the imperial gallon)

I went to the German site for the same car (http://www.honda.de/content/automobile/modelle_jazz_technische_daten.php) and it uses 6.5L/100km which works out to be 1.7 US gallons per 62.5 miles or 36.7 mpg (check my math here please?).

which is only ~20% difference.

[Blue Meany]

8. I don't think its just engine size..

I think it is the weight and size of the cars. The first car I owned was a 1960s-era British car (Lloyd Alexandria). It was so light two people could lift up one end of it. It had a 2-cylinder engine and got close to 40 mpg. This was in 1970, when no one cared much about gas mileage.

[14thColony]

9. But the point the OP made was

that they were identical models, just with different names. Those two chassis would have virtually no difference in weight, except for the different engines and possibly different transmissions. I'm pretty sure my UK XC90 is the same weight as a US XC90, except that my D5 diesel engine might be slightly heavier or slightly lighter that the US gas engine.

[sui generis]

3. that was masturbatory

Add, Europe generally has better maintained highways, greater use of manual transmission, and far less use of air conditioning. I don't know how much of the difference that accounts for but it's a bit soon to say there's no room for improvement in U.S. gas mileage.

[Cessna Invesco Palin]

5. Frequent use of air conditioning doesn't mean the car itself is any less efficient...

...it just means it's being operated in a less efficient manner.

[Captain Hilts]

11. At high speeds, it kills fuel efficiency to have the windows open. So you break even. nt

[napi21]

4. Diesel power is thebiggest reason.

[trotsky]

7. Car Talk is awesome.

Don't drive like my brother.

[Captain Hilts]

10. And don't drive like my brother. nt