I'm with Andy on this one, and
most others. When you underinflate a tire drastically, you increase the heat
BIG TIME. But then again, I don't get paid 6 figures a year, so I know nothing
At any point, this thread turned into a pissing match of sorts.....sorry to ramble like that.
If it were me, I'd run the tires at or just below the max. inflation specs. My friends dad had an original honda civic (early 70's), and got 89,000 miles out of the tires, and they were still on it when he sold the car....all he did was check the tires at every fillup (he's really anal), and kept them filled to spec. The heavy rated tire is gonna mess your ride up some, but I wouldn't underinflate it to compensate, I think it'd be a really bad idea.