In my H2 SUT, I towed about 8000lbs (K5 full size Blazer and the trailer) from Atlanta Ga to Murphy NC which goes directly over the mountains. It towed just fine. Not like an F250 diesel, but fine. I slowed to about 35 MPH on the steepes grades and got about 7.5 MPG throught the mountains
but, it usually gets 11 MPG for me, and about 9MPG for non mountains towing. IMO they are way more comfortable and quiet that an H3. H2 takes up every bit if a parking space though, and cant fit in to some compact spots in the cities.