1995 camaro z28 six speed. 3.42 gears.

when i first bought my car, and the summer after, i averaged to get 300 miles out of a tank, or usually about 20mpg combined highway and city, mostly city. over this winter, i average 200 miles out of a tank. this is killing me. is it because of the cold weather? i cleaned my k&n filter and that did not help. a 33% sudden drop off of a fairly fresh motor is not a good sign for me. any ideas of this sudden drop? thanks

 

Do you let the engine idle for a while to let it warm up? Sitting still with the engine running gives you zero miles to the gallon, and affects your overall average. Also, some areas have a "winter blend" of gas that contains more ethanol than the summer blend (summer is usually 10%). A higher percentage of ethanol in the gas lowers your mpg's. Read the label on the gas pump, it tells how much ethanol is in the gas. If you don't like what you read, try a different gas station.

 

^ Truth.

The winter blend gas is a joke. >.< It seriously makes me mad because my average mileage usually drops from 22 to 18. :/

 

scann it and see if the 02s or mas are acting up. could try an reset the computer by unhookin the battery for a while. scann first unhooking battery clears the codes.