Hi, Can anyone explain what the difference is between summer and winter gas - and why my mileage drops in winter? I've heard the winter blend is "oxygenated" - why the change and what exactly are they doing to the gas?
Here in Illinois, my 2003 Forester XS gets 27-28 mpg in mostly highway driving - in summer. As soon as it gets cold, that will drop to 23-24 mpg, same driving situation. This is using same gas brands - all with ethanol.
What makes me crazy, a friend who drives Hondas says his mileage is same , year round. My wife's Chevy Cavalier (!), gets 29 -30 mpg year round. Why is Subaru not able to compensate for the gas difference?
I've tried the pull the battery cpu reset - the car just drives poorly for awhile, then back to same situation after 2 or 3 tankfuls. Thanks, in advance, for any info...