I am looking at various A/T tires including the BFG A/T's and the Nitto Terra Grapplers. Both are offered in both D and E load rating.
Is the load rating directly related to the strength of the tire? Does it have any effect on the treadlife of the tire? Basically, if I put D Rated BFG's on the my truck, will they last just as long as the same size E Rated BFG's? That being said, I would properly rotate them etc. I would like something smoother than E Rated, I don't do any pulling, minor off roading, so highway comfort is important, so if D Rated tires will last the same, I'd prefer to go with them. Discount Tire here in Laredo told me I had to go with E Rated, but I guess the customer ultimately decides.
Also, is there a difference in the tires heat rating? I live in Laredo, Texas where it can easily get 105-110 degrees and I do quite a bit of highway driving on not so great highways and I want something that is resistant to heat. Are E Rated tires more likely to hold up better than D rated tires under the same heat extremes?
Basically, is the rubber compund the same in each the D and E rated tires and the steel ply's are different, or is it a completely different compound?
Hopefully I am clear in my question.
If not, let me know and I'll elaborate.
When choosing a tire there are a lot of things to consider, Size, brand, tread design, Load index, # of plies, sometimes Tread Ware rating, and even Traction and temperature ratings.
In general when selecting a new tire here are the main things you need to consider in no particular order.
1. Size. Too many people take this too lightly. When selecting a tire size stick within the Tire manufacturer's recommendations for rim width. Tires are designed to flex in certain areas, if you pinch or stretch a tire on the wrong size wheel your tires life will be significantly reduced and your risk of tire failure will increase and any and all warranties will be void. Stick within these recommendations to keep safe and help you get more out of your tires in terms of life and performance.
2. Load index. Tires have a load index # indicated on their side wall. This number indicates the maximum carrying capacity of the tire. It is very important to maintain an equal or greater load index to that of your vehicles original tire. Runner a tire with a lower load index will increase your risk of tire failure, reduce your tires life and any and all tire warranties will be void.
3. Plies (Light Truck Tires). E tires are rated = to 10, D = 8 and C = 6. This is very tricky to explain because some of this is effected by size.
LT Tires that are 295 or narrower have higher max pressures than LT tires that are 305 or higher. We indicate this on our website by adding the numbers "1" or "2" after the ply letter
If comparing two tires in the same, size, brand, model and load index, the higher ply tire will have a higher max pressure. Higher max pressures reduce a tires flex under load and increase the tire's lateral stability.
4. Tread rating also stated at UTQG. This is not based on an industry standard of testing. Each tire manufacture sets their own tests and determines their own ratings. Only compare UTQG's within a brand i.e. one Michelin tire vs another Michelin tire. Do not compare UTQG's from say Goodyear to Michelin.
Some AT tires, not all, have a tread ware rating. Generally speaking, the higher the UTQG, the harder the rubber compound. Tires with harder rubber compounds generally last longer than tires with softer rubber compounds. This usually comes as a trade off of traction and grip. Tire manufactures may or may not use the same rubber compounds in different sizes.
I hope this helps straighten some of these things out for you. There are many, many factors that determine a tires life and performance. There is a lot to grasp here so if you would like some more detailed help in selecting a tire that will be best for your application please call us at 1.888.459.4080 or please stop into a local Discount Tire or America's Tire. We would love to earn your business and we are happy to help explain anything you may want to know before making a purchase.