I'm actually more worried about time than mileage. I ride the bus to work. I only drive on Saturdays. Now that I have two Crossfires, the mileage I'll be putting on them is minimal, probably less than 2,000 miles/yr on the SRT-6 and less than 4,000 miles/yr on the coupe. At that rate, the SRT-6 will get one oil change every three years and the coupe one every other year. Should I change the oil after a set amount of time or is mileage really all that matters?