I'm running E rated tires, 80 psi max., I run 55-60 psi in them. I'll need new tires this fall, and am wondering if it makes sense to go to D rated tires, 65 psi max. I don't tow heavy, 4,000 lbs. max, but not sure if the D's are OK on a 3/4 ton Suburban. I'm assuming they would ride better than the E's. Opinions?

Ride softness will improve, but you may not like the "wobbly" feeling you might get. I just replaced the tires on mine and stayed with E range for that reason; I do keep them around the same pressures as you when not towing heavy.

comes down to load if the front or rear axle becomes hevier than the weight marked on the tires (x2 cause you have 2 tires with that rating) than they will over heat and blow out. Knowing that figure out what your truck weighs empty then add the load and check your numbers. Also the LRE give you better stability not give you that sway feeling the LRD will. You can always go to a more touring tire like Michilin LRE and simply run it at 55 unloaded and then bump it up when loaded, also new shocks like blistens would improve ride.

I'll check the load rating, I doubt that would be a problem. Both of you mention that the D's might sway or wobble, that would be enough to keep me with the E's. I don't really mind the ride I have, its fine on the highway just a bit hard on rough roads. Some better tires would help, so maybe I won't take the chance and just stay with the E's.

I went with Michelin LTX M/S tires and am happy with them. When you go tire shopping, feel the sidewalls on an E and a D tire, you'll notice the difference.

I ran LTX M/S on my Durango, great tires. I didn't realize they come in LRE. I'll certainly look at them.

My other problem is size - my 235/85-16 are about an inch larger than the stock 245/75-16. While I don't want to go with much wider tires, want to keep mileage where it is, I don't want to go down in diameter either. With my 4.10 axle it spins fast enough on the highway now, I don't want to gain another 100 rpms with the stock tires. So, I'll have to stay with the 235/85 size or go to 265/75 (more common and more choices) to keep the diameter I have now.

So, I'll have to stay with the 235/85 size or go to 265/75 (more common and more choices) to keep the diameter I have now.

I'd go with the 265/75/16 over the 235/85/16 because the 265's will give you a bit more width than the 235/85 which will help with stability, especially when your towing.

Has anyone run the same tire in a D range and an E range on the same truck? and what differences did you notice?