One of the most common questions that people ask when they learn that I drive a hybrid is whether or not they actually get the advertised mileage. The reason this is such a common question is because the EPA mileage numbers that are used in the U.S. are based on a test that is not indicative of a normal person’s driving habits– the test is biased towards low speeds, gradual acceleration, and other hybrid-friendly scenarios. The result is that most people don’t manage to equal the EPA estimates unless they significantly alter their driving style.
Fortunately, last year the EPA announced it will change its fuel-economy testing procedures to better map to regular consumers’ actual fuel use. This is a good thing, even though EPA mileage estimates will drop for hybrid cars by as much as 20-30% by some estimates: it will encourage manufacturers to optimize vehicles for normal driving conditions instead of the arbitrary and bizzare set of old EPA tests.
However, my driving style and route to work map very well to the old tests… so the question is which estimates should I use? I’m going to use the updated 2008 estimates whenever possible just so that I can compare apples to apples, since I’ll be buying when everyone has switched over to the 2008 model year.