Hi Guys,

I was thinking of moving up to 285/70/ 17's from my stock michelin 265/70/17's on the stock rims. My question is, how important is the e rating? The reason I ask is, for pirelli scoprion ATR's, one of the tires I am considering, The 265/70/17's are E rated while the 285/70/17's are D rated but they have the exact same max load rating at 3197 pounds. Why is one D rated and the other E rated?

 

The load rating can be the same, but the sidewall "ply" is different. "E's" will have less sidewall bulge and will not flex as much when under a load, especially on rough roads and turns.

If you're going to haul or tow heavy, it's best to stay with the "E" rated tire.

Don't ask me how I know..............

 

Different ply side walls. I had a D rated BFG 315 on my old 04.5 SRW. They were rated the same as my stock 265's @ 3195 pounds. HUGE difference in side wall flex with my 5er hooked up. Then I moved to 35 inch Toyo mud and it was E rated, with 10 ply sidewalls I believe, way better with 5er in tow. I would stay with the E rated 285's if I were in your shoes again. I had the 285 E rated toyo A/T on it when I sold it and they are a great tire in my book. good luck . . .

 

The weight rating is most important, but like crobtex said, the load range rating is a better indicator of tire stability.

My 325/70-17 tires are good for 3305 lb, but they are D-rated. So I can pull the heavy load, but I can feel it acting more squirmy than with an E-rated tire.

 

^^^^ what they said. If you tow heavy (tag or fiver) stay with an E rated tire.

 

Load rating tells you how much air pressure your tire can handle.

Tire size and air pressure combined determine how much weight your tire can carry.

Two tires that are the same size, and are set at the same air pressure have the same weight capacity, regardless of there Load rating.

Example:
If you run your tires at 60psi. the weight capacity will be the same whether you have a load range D or a load range E tire. The difference is with the load range E tire you can put in more air to increase the weight capacity. Remember that is with the same size tires that have different load rating.

If you are trying to compare different size tires then the weights changes.

The most important thing to remember is the weight capacity on the side of the tire is figured when the tire is at maximum air pressure.

 

I have run many hundreds of thousands of miles driving, hauling, and towing heavy on high load rated D tires...nevr a performance, saftey, or legal hassle.

I stick to the numbers...not the letters.

 

I've been running Ds on my truck for about 100,000 miles now. Not saying everyone should but when I went to 315s and later to 285s there were not many choices on the rating. In fact I put on H2 takeoffs that were D rated. They have all been good. But for heavy towing the E rating is a stiffer tire. Not rated to carry more (265 E vs 315 D) but a stiffer tire that can also run more pressure. I'm getting ready for new tires again and this time I've decided to go with E.

Remember that they are NOT 10 plys. They are E rated. Not that it's a big deal but most tires these days are either two ply or three ply sidewall. They tell you 10 ply at the tire store but they are not. The magic word is "rated". In other words, they are rated as strong as a 10 ply but they are two ply. Kind of bugs me to advertise and mis-lead that way. And even the load range E radials have a vulnerable sidewall compared to the old fashioned bias ply, true ten ply tires. But modern radials are WAY better for normal use. If I was hauling broken rock from a mine out in the desert I'd want the true ten ply tires but for highway towing the two ply radial is much more efficient and has better traction.


John