winter months will tend to get worse mileage, simply because it takes longer to get to operating temp. Directly proprotional to the air temp outside, meanig that a engine at 32* is alot warmer on start up then one that is -32*
the exclusion to this is if you're in a more southern climate, never below 32*
driving habits are often adding up to worse MPG's then folks realize. Maybe you were taking it easy on it when you 1st got it and as you got to know each other more...more right pedel followed. Just running a senerio mind you, not necessarly saying that is what is happening.
if your driving habits are the same....then a good tune up is the place to start.
