Turning the ac does absolutely NOTHING to mileage in these trucks. I've monitored it extensively. I get around 19mpg highway w/ stock crappy air filter, going about 70-76mph. I have an auto.

 

i think u right, last summer, 17-18 with air on 100% and that takes power for comp.

winter, 16 and heat is free, not much fan use

its HOT now but i dont like even talking winter,,sorry,,wont happen,,

tom

 

I've documented my mileage over the same strech of highway, 600miles round trip, several times with ac on and without ac on. No difference in mileage. Maybe tenths of an mpg lol.

As far as winter, I keep my house a steady 61* all summer long. My kids call me the snowman hehe.

 

haha so I sweated for nothing...

 

yep pretty much.

It's ok though, I was doing the same thing until I couldn't stand the sweat/leather anymore and cracked and started using ac the whole trip. No documented changes in mpg worth noting.