I'm at 3500 miles,
and my milage has acutually gone down. 31-33 mpg from 35-36..
I have driven at all different speeds, but mostly old lady driving @ 60 mph..
the 38+ mpg posted here by people is a buch of bull IMO..
My old car (given to daughter was a Honda civic hybrid....driven at 60 mph it regularly gave me 46-48 mpg..
here is a link to my fuelly profile:
http://www.fuelly.com/driver/kupp/focus
the high economy rating for one fill up of 48.2 mpg is balanced out by the previous economy of 31.7. On that tank it was overfilled, thus making it seem as though I went through more fuel resulting in the lower rating on that tank, and the surplus fuel resulting in more distance traveled on the subsequent tanks. It balances out.
Overall with 19 fill ups and at this moment 6305 miles tracked my average fuel economy for how I drive is 37.7 mpg.
I always pump the gas until the cutoff stops the pump twice, and I try to always use the same pump at the station if I can help it, just to keep everything consistent. When I fill her up, depending on how I have been driving recently, it usually gives me a reading of between 448 and 488 miles for Distance Till Empty.
I also have the SFE package on my car, which is a factor.
But driving methods, fuel quality, and traffic conditions are all contributing factors.
If your economy is dropping, as mine has with outside temperature, have you checked your tire pressure?