One of the deciding factors in our Yukon XL purchase was wheel cut. We test drove Sierra AT4X trucks, and were very close, but found they had a much larger turn radius than their SUV counterparts. I've searched for an answer but don't know why the Yukons turn so much tighter than the Sierras. Same can be said for Tahoe/Burb vs Silverado. Don't these use suspensions/frames that are VERY similar on the front?