Here's the specs on two tires from the same manufacturer:

265/70R17 Load Range D
121/118R Load Index
3195 lbs. Max Load
80 psi Max Inflation
10.7" Width
31.7" Diameter
659 Revs Per Mile

285/70R17 Load Range D
121/118R Load Index
3195 lbs. Max Load
65 psi Max Inflation
32.8"
637

I'm no tire expert other than just comparing specs on tires and doing research. I've got the 285/70R17 tires on my truck right now (bought used with them on there) and have often heard about always using Load range E tires when towing heavy loads. I assumed this had something to do with the load rating of the tires. However, the Load range E version of this tire (in the 265/70R17) does not provide any higher load rating-even at a higher inflation.

I'm sure there are quite a few of you that can weigh in on this one-I'm at a loss. I assumed that I would need to move up to a Load Range E but no matter which tire I research in Load range E they max at 3195 lbs. load just the same as the Range D above in the 285/70R17.

I understand a Load range E tire in 16" size is in the 3415 lbs. range but I assume that the maximum load on a tire is when hauling and not necessarily towing. The tongue load for the maximum trailer rating should be around 1200-1300 lbs.

 

The difference in the tires is mainly in the sidewall strength. The load range E can handle more psi (80 vs 65) so there is less sidewall flex and so less heat generated. The 285 ''D'' rated tire will carry similar weight as a 265 "E'' rated tire because of more sqare inches of tread on the ground. If you are going to be hauling maximum weight on a regular basis the "E" rated tire would be better for long term performance, otherwise the "D" rated tire will probably be sufficient.