I would also add fuel or gasoline formulation.
Diesel #2 is mixed with diesel #1 (Kerosene) to a certain amount.
The more #1 you get the less fuel economy.
Less BTU's per volume.
I guess it's the same for gasoline.
So that's why there's a 14 mpg difference in between February and August. :blink:
There are mods you can do to recuperate part of mileage lost because of weather...
