How does the Hummer H3 handle the mountains, I'm talking about the passes in Colorado, Loveland pass, Vail Pass, the grade is so steep my 03 Tahoe pulling a popup camper had issues. I test drove one today and love it. And how do they do towing? Thanks

 

5.3 V8, 3.7 or 3.5 I5?

 

I have towed a small utility trailer (about 1500 lbs) through the hills on 33's and 35's with my 3.7l, I would not tow on 35's on the hwy unless I had to for very short periods and even then I would stay under 60-65. Around town it does fine, wind resistance and high speeds make it pretty unpleasant. I would also make sure I fit an oil cooler if it is an automatic, every bit helps! I have not driven the V-8, but I hear it makes towing much nicer.