What's the difference between a tire with a Load Range "D" that will allow for a MAX Load weight of 3195lbs@50psi and a Load Range "E" with a MAX Load weight of 3195lbs@65psi? I've read that D has 8ply & E has 10ply. How different is that, besides the obvious? Trying to decide on the BFG AT T/A K/O LT305/65R/17E and the LT315/70R/17D tires. This is an awesome sight.
The 10 ply or Load Range E tires can take a heavier load. You can inflate a 10 ply tire to 80 PSI. It gives you a little more of a safety margin. About the last thing you want when you're towing is a tire failure.
A lot of guys that don't tow will use Load Range D tires. You'll get a little smoother ride out of those, everything else being equal.
I don't mean to point out the obvious, but when calculating the load capacity of your tires don't forget to take into account the empty weight of the truck itself that the tires will be supporting.
Example: E rated tires can support 3415 lbs, times 2, that's 6830 lbs. Subtract the rear axle weight of your truck (not sure what that is, let's say it's 3000 lbs for simplicity). 6830-3000 = 3830 lbs you can add to the rear of your truck.
I think this makes sense, let me know if i'm all wet. Again not trying to be a smart butt, just wanted to point this out. .
You're right sandman3510, but not all "E" or "D" for that matter hold exactly the same. So, not all "E"s will be 3415. BFG makes a lot at 3195 and Toyo makes at least one that's like 3800 of something.
As Redford pointed out there will be more sidewall flex, "squirm", with the D tires, but they'll hold up the same weight if rated the same. You'll just feel it a little more when cornering, braking, etc.
I just went from an "E" to a "D" and notice the sidewall flex quite a bit. The "E"s were STIFF. The "D"s provide a much better ride; although both are rated at 3195. I bought the "D"s knowing that though and it was part of the reason I went that route.
The "ply" identification number has no meaning anymore. It was used to indicate the number of belts or layers of materials. The new letter designation is an equivalent indicating for example an "E" rated tire is equivalent to an older tire with 10 plys or layers. The development of new materials means my OEM BF Goodrich tires probably have only four belts.
Very good point Sandman. In addition, do not forget a fudge factor in case of the loss of a tire by catastrophic failure. Have friend who had three tires go in succession (blow-out) on a heavy loaded trailer. Of course person never checked them before hauling. Duallies share the load in case of tire failure and engineers considered in the tire specifications.
Last edited by HorseyHauler; 12-05-2007 at 02:19 PM.