According to the EPA, even though each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.

As a rule of thumb, you can assume that each 5 mph you drive over 60 mph is like paying an additional $0.20 per gallon for gas.

Slowing down can increase your fuel economy anywhere from 7% to 23%. And, as an added bonus, it's also safer.

This page was created 06-25-2008, however the content may have been pre-existing on a different page.