Quote Originally Posted by joshi View Post
Marlin - "colder air should get you better mpg" I think is not right ....
The drag has to do with the weight of the air that has to be pushed aside and pushes against the vehicle motion. Take for example, swinging you hand through water, a very dense fluid, versus air, a much less dense fluid. As the air gets colder and colder, it becomes denser and like water, becomes harder to move through.
Air becomes more dense as temperatures drop, which increases air resistance. For every 10° F drop in temperature, aerodynamic drag increases by 2%. Thus, fuel efficiency will drop by 1%. Overall, fuel economy tends to be higher in the summer than the winter. According to North American Truckload Fleet Data, driving in the summer increases fuel mileage by 8 to 12% over driving in the winter months.
Hmmm, I was thinking the mpg drop for winter driving had to do with the transition to winter diesel. They add the anti-gelling junk to it, and thus raise the price They already had it out in Missouri. It was 3.19/gal there versus the 2.89-2.99 I pay here