Hi, I have a 2000 chevy cavalier and it all of a sudden started getting horrible gas mileage. I was getting 26mpg in the city. Now I have getting 17mpg highway and lesser than that in the city. I've checked for fuel and vacuum leaks, the spark plugs and wires, air filter, tire pressure and have found nothing wrong. The car runs great and doesnt smell like gas or idle rough. The car runs perfectly normal like it always did but before winter started it suddenly dropped. I have a flowmaster delta 40 muffler on it but I took my calculation of 26mpg after it was installed. I understand the winter takes away some fuel mileage but by how much I lost I think something else could be wrong with it. Can you help?
Monday, February 14th, 2011 AT 9:02 PM