Why do European cars get better MPG than their US equivalents?

Dear Car Talk

Dear Car Talk | Jan 01, 2010

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

TOM: 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?

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