the colder the air, the denser it is. so, during the winter, denser air gets sucked into the engine. subsequently, more fuel must be used to match that denser air.

 

Don't forget fuel companies add some type of detergent to the fuel pumps so they do not freeze. That winter agent also hurts performance.

 

performance is always and has always been better for me in the winter. engine is always noticably stronger. it's only the gas milage that suffers. which, again, is an indication of the denser air.

but i haven't heard of this winter agent before, so there may be something to that.

 

Shit the reason I thought my gas mileage was going way down was because I always warm my car up in the morning. I'm sure that contributes to the usage of gas, but I guess my CAI dosen't help either

 

most recent tank ~272 miles. but it was more highway than usual. normal days where i go to school and work, i get about 240-250 miles.

 

I used to get like 420 or so on a tank, now I'm lucky to get 350.