Buzz70 has posted several years worth of mpg data into our database. His car Voltswagon gets the worst mileage in the winter as might be expected. The peaks are June and September when the temps are warm but no AC is needed. July and August take a little dip due to AC use (I assume). July and August are still higher than the winter numbers, verifing what everybody else has already said in a graphic way. Check his car out at:

http://www.greenhybrid.com/compare/m...oltswagon.html