Well I've had my new 2012 since late July and must admit I don't drive it a whole lot. I have it for my antique tractor collection for the most part. I did break it in for about 700 miles until I towed with it. This weekend I finially got the time to go to a antique tractor show about 140 miles away from me so it was time to see what the 6.7 got. I was going threw the center part of Pennsylvania and let me tell you the hills are long and steep on the interstate. I was amazed at the power!! I had the cruise set at 65-70 most of the time and when it would get to a hill it wouldn't even down shift. I would be going up hill at 70 mph around 1,900 RPM.. I had a 6.0 before this and was happy with it,but WOW there is no compairson. The trailer itself is around 6,100 lbs and the tractor I had on it is around 3,500 = 9,600 lbs total. Didn't even know it was there.