I've owned about 25 cars so far but never have I owned one as amazing as this one on gas! The car is heavy, somewhat slow to accelerate and doesn't feel sporty in any way. However it rides like you're on a cloud and on the highway I regularly achieve 34 mpg (at 75 mph) and have even gotten one trip at 38 mpg which is phenomenal for a car of this size and weight. Its already got 260,000 km on it but still running strong. I think the 3.8 is the best engine GM has ever produced.