12-16-06, 11:17 PM
I recently bought a 2007 STS with a V6 and the luxury performance package. I'm dissapointed to find that my fuel mileage on the highway is only about 23MPG cruising about 60-70 MPH. The car that I had before this was a 2005 CTS with the same engine and final drive and got 27 MPG on the highway. Although the CTS was 300 lbs. lighter, on trips with another person and luggage in the car to make up for the 300 lbs. difference the mileage was still about 27 MPG. Can anyone give me some comparisons on their cars fuel mileage or an answer on why I get such awful mileage on two cars that are so similar. Even my 2001 STS with a V8 got 24 MPG on the highway.