I have a question regarding our `02 Grand Prix. Normally we get around 25-34mpg or 400-425 miles on a tank of gas and recently we have gotten REALLY bad gas mileage. Couple of things have changed, we live in WI, so it is cold, which means sometimes we let the car run for awhile before we drive it to warm it up. This last tank I had about 80 miles of highway driving but the rest was in town and idling. Anyhow, this tank will only get about 250 miles on the tank. We have never gotten that bad of gas mileage in the last 60k miles we`ve had it. Also, there is a little smell that I have started noticing. Not a gasoline smell, almost like a propane or other `gas` smell. Any ideas?
Cold weather has an affect on mileage, but not that much. If you smell a bad odor, check to make sure the catalytic converter isn't plugging. Also, check for tune up and if the check engine light is on, have it scanned for codes. Most parts stores will do it for free.