[bsmith0404]

I towed with a GMC 6.0. The trailer I had at that time was around 9k lbs loaded. Put a boat behind the 5er a couple times which put me up to the 11k lb range. My experience/opinion, the truck towed fine on level ground, struggled on hills, and never passed a gas station (8 mpg). When our camper was destroyed by hail, we upgraded to a 5er that was about 12k lbs, a duramax was a must for me before making that move. The difference, 11-12 mpg, so much torque that it seldom downshifts, and cruises over hills and mountain passes like there's nothing behind it. Main difference, big smile on my face! Go with a diesel. The newer ones are pricey, but they are also a dream to drive for many reasons, exhaust brake and integrated brake controller just to name a couple.