The 6.6 Duramax is one of the most powerful engines for heavy-duty trucks like the Chevy Silverado and GMC Sierra, but how ...

For a 1999 F250 Super Duty with the Power Stroke 7.3, Fuelly cites 148 owners as reporting an average fuel economy figure of 14.41 miles per gallon (MPG) over more than three million miles of driving.

For the sake of comparison, TrueCar data shows that back in mid-2008, the average fuel economy rating of light vehicles stood at 21.2 mpg. In our opinion, that's a barely measurable improvement in ...

Better yet, May represented a monthly record high. May's new cars got an average fuel-economy rating of 25.6 miles per gallon, up from 25.2 mpg in April and rising 3.2 percent from the 24.8 mpg ...