What speed is used to calculate MPG?

Question

If a certain car is rated 20 MPG in city and 30 MPG on the highway, then what is the city speed and what is the highway speed used?

Answer 1

Highway MPG is tested over 12 minutes at speeds between 0 and 60mph.  City MPG is tested over 22 minutes at varied speed range between 0 and 60mph.

Here is the link to how the EPA tests vehicles for MPG: http://www.fueleconomy.gov/f*g/how_teste...

Interestingly, here is a QUOTE from their site:

"Fuel economy is measured under controlled conditions in a laboratory using a standardized test procedure specified by federal law. Manufacturers test their own vehicles—usually pre-production prototypes—and report the results to EPA. EPA reviews the results and confirms about 10-15 percent of them through their own tests at the National Vehicles and Fuel Emissions Laboratory."

Here is a link to the CURRENT testing procedures ordered by the EPA : http://www.fueleconomy.gov/f*g/fe_test_s...

Alittle AMUSING to think they can generate ANYTHING near accurate information using such SHORT test times !!

Answer 2

Traditionally, 30mph is used for city and 55mph is used for highway.

But recently the formula has changed and they integrate a whole bunch of different factors and it's no longer a speed specific test.