[Rickster]

Hard to say.

In your area do they put any "addatives" in your gas for the winter?

Does your car get worse mileage in the winter?

Up here in Mn we have 10% ethonal in our gas, and I always get 5 mpg better mileage when I'm traveling through a state that doesn't add ethonal.

After I had the dyno tune done on my Road King I started playing with the Power Commander, and after about 2000 miles of trial & error, I ended up with about a 10% leaner map than the computer had set up. The result was a 8 mpg gain in fuel mileage, and no felt difference in performance.