The Larger tire displaces the weight throughout the tire. that makes it handle more wieght. Just think of a large tire on a piece of farm equipment. The Large tire on a Combine will hold 10,000 to 20,000 pounds a piece with 10 to 15 psi and stand up good. That wieght is being distribed throughtout the inside surface area of the tire.

 

Thats how I understood it but that puts me back to step one again. Why is the load rated E tire better than the D that has a higher weight load?

 

Because the E has stronger sidewall!!!

 

Because weight rating is not the most important factor when picking a tire.

If you are towing the load range is just as important, if not more important than weight rating.

The greater the load range the stiffer the sidewall and the more stable the tire will be at proper inflation because it holds 80psi vs a D rated tires 65psi. When towing both of these factors are very important. You do not want your truck to wander when you have 10,000+ lbs behind you. On a long trip this really gets to be a PIA.

If you start searching some of the RV forums you will see that a D rated tire is not optimal for towing a decent amount of weight behind you on long trips.

As I said before if you are running empty 99% of the time and/or your loaded trips are very short in distance the D's will probably suit you just fine, but if you bought your truck to be your "tow rig" I would not recommend D rated tires.

FWIW - I run a D tire and tow a maximum of 9,000 lbs a few times a year. I do not have any real problems with my D's but I never travel more than 25 miles with the trailer behind me. I do notice a little more wander now with the D's than when I had E rated tires, but in the short distances I travel it is really not that much of an issue to me.

 

I have added an image to my gallery that shows the 2004 Tire and Rim Association official wording. I do not know how to add images directly to this message. I just uploaded the images so they make take a while to show up.