You just said the smaller E rated tire has stiffer sidewalls....making it a better (less roll ) towing tire. Even if a D rated tire is rated for the same or more weight.

 

My assumption is if BFG states their 315 "D"s are good for 3200 lbs a tire then a guy should be able to put 3200 pounds of weight on them, no ?

 

That would be my asumption as well. Personaly I have towed heavy with the stock 265s a set of 295s and 2 sets of 285s and honestly I cant tell one iota of diference.

 

I could be wrong but D rated vs E rated has to do with side wall and tred ply. I think D are 8 ply and E are 10 ply. Also something about the heating they can with stand and the speed at which they can cary their max load as well. I had truck camper that put 6000-6500 on the axle depending on loading and the E ran a little cooler going 70 mph compaired to my BFG AT at a D rating with a higher weight capacity. Never felt unsafe though and they never seemed to hot to me. Wear was fine to. Probably did 10k a year when i was fishing alot.