I have noticed that the fuel mileage in my '00 SL1 has slowly been deteriorating over the last few months. I am currently only getting aroun 22-24 MPG (dpending on how accurate my conversion is). I feel that I should be getting better, especially since the pric of gas has increased so dramatically... The car is an automatic, and has been well maintained since new. It has 65,000 kms on it and I have owned it since 40,000. The air filter was changed at 52,000 as were the tranny fluid and filter, and spark plugs. I change the oil as soon as the light comes on. I was told by someone that the O2 sensor May be the culprit, but I wanted to ask some people in the know before I take it somewhere to have it looked at. Any ideas or recommendations?