Edmunds: Here's Why Real-World MPG Doesn't Match EPA Ratings

[valkraider]

Here is an interesting article on Edmunds about the EPA ratings and real world mileage:

Here's Why Real-World MPG Doesn't Match EPA Ratings

 

I broke down a lot of other reasons in a post here:

 

Essentially there are a ton of differences between the EPA tests and how we drive.

 

However, this Edmunds article also pointed out a couple tidbits which I did not mention in my other post:

 

EPA tests are done with 100% gasoline, zero ethanol.

Fuel type also affects mileage. Most gasoline in the U.S. today is 8-10 percent ethanol, but the EPA does its tests with 100 percent gasoline in the tank. The use of ethanol to increase the amount of oxygen in gasoline for better combustion can reduce fuel efficiency by around 2 percent all by itself.

 

EPA tests are not actually *driven*

And even though the EPA's test system was modified in 1984 and 2008 to try to make it more relevant, it still doesn't precisely reflect real-world driving. The EPA still uses stationary laboratory tests run on a dynamometer, which ensures repeatability but not necessarily the driving experience of consumers.

[skwcrj]

Great information. Nice find.