Re: How much does winter gas decrease mileage?
It also takes longer for the engine to warm up. This keeps coolant temp sensors cold for a longer time and keeps the fuel injection running rich for longer periods. Rich mixtures also help light off the cat quicker and keep pollution out of the air. In real cold climates, I assume it's a habit to leave your car warming up in the driveway and keep the engine idling for longer periods to keep the heater and defroster going. We Kalifornians get a real crappy winter blend gas that is full of "oxygenates". This stuff is similar to E10 that is found elsewhere and reduces fuel mileage. It's sold to us as helping our global climate but in the end just makes you use more gas, lightens your wallet quicker and makes cars runs bad.
2007 Colorado, Pace Blue, regular cab, 3.7, auto, ZQ8 , 2LT , 3.73, G80, tow package
Pace Edwards Jack Rabbit bed cover
Catch-All Xtreme Floor Guards
ZQ8 tailgate decal
Factory foglights added