The wife and kid took a trip this weekend to do some shopping. Since she drives the Acadia 90%+ of the time I decided to drive it. Wanted to track mileage because she never does and the average economy is usually around 18-18.5. Have been kind of disapointed in that so I thought I'd track it. Heading out for the first 200 miles it got right at 24.5 mpg. All highway no wind/hills (I live in Kansas). So that was great I thought. Never seen it that high. About 100 miles of town driving and another 200 or so miles back home bucking a pretty good wind and the average economy was 21.2 computer calculated. I checked that against my hand calcs and it was pretty close to the same thing. So all in all I'm pretty happy with that. Do the engines start getting a little better mileage as they get broke in? Our's has 18,000 on it now. May have been a fluke, maybe had good gas, the temp's were mild, I don't know, but that's significantly better than it had been getting. Maybe my wife has a lead foot! When we bought this last year I really wanted the Yukon (mainly because of the huge rebates offered) but she wanted the Acadia. So far I've been impressed with it, but still perfer a larger vehicle. With the mileage it had been averaging I was let down from what the sticker had claimed. But if I can get 24 on the highway again I'll be pretty happy. The only thing I really don't care for is the constant shifting from 6th to 5th with almost any type of incline. It drives me nuts.