Tire Codes and Ratings

[Dogmeat]

Something got me thinking with all the talk about tires on here, so I decided to look something up:

http://en.wikipedia.org/wiki/Tire_code

Apparently "Load Range" has nothing to do with how much weight a tire is actually rated to carry, it has to do with what they are calling a "ply rating", which is not to be confused with the actual number of plies a tire is made from.

Interesting.

So apparently, something that is LT specified and Load Range C is a "6 ply" tire, Load Range D is an 8 ply, and E is a 10 ply. At least in ply rating.

Looks like my next tires will be Load Range D 265/70/17 duratracs

 

[AZ800]

That is correct. I've never understood the hype about "don't put D rated tires on a 3/4 ton, they won't handle the weight."
SOme E tires are only rated asheavy as some D tires. SOme E tires are heavier.
DOn't worry about the D tires unless you have alot of bed weight or pin weight. I've had multiple sets of D tires on HD trucks and for normal use/towing they are fine and last just as long.
That said, if I was pulling a 15klb 5ver all over the place I would get some stout E tires like Toyos that are rated for almost 4klb.

 

[Coldfinger]

I've got D rated 265 tires on my GMC Crew 2500. Stock tire was E rated 245.

The load rating is or nearly is identical.

I think the E rated tire gives more lateral stability though which is better when you start hauling or pulling heavy loads, but let's hear what others say because this is the only time I've had E tires.

When I had the E tires on it I didn't have the camper trailer so I never pulled more than a open sled trailer. I don't know how it would have felt under heavy load, I can only guess.

Of the tires I considered, you could get the same load rating from a D tire but you had to go up in size. My 245/75-16 E has the same load rating as my 265/75-16 D.

 

[Dogmeat]

I guess my question then becomes ... what is "ply rating" .... Because it isn't the actual number of plies, and the load index is what specifies how much weight a tire is rated to carry .... So what is "ply rating"?

 

[Dogmeat]

http://en.wikipedia.org/wiki/Tire#Ply

Well ...

I guess if you're towing a heavy load, a higher ply rating would probably be better, hence why they always put E rated tires on 3/4 ton and 1-ton trucks.

Probably wouldn't want that for a half ton.

Ah well, guess I'll stick with the E-rated tires.

 

[ottawaair]

E load tire have more lateral control. Stiffer sidewall, maybe not more plys, possibly thicker ply ? Either way, they are rated to carry more weight, and the manufacturers are required to install a tire rated to handle the maximum capacity of the truck. Be it in the bed trailer.
Basically, if u use D range tires, just make sure you don't exceed the rated capacity. Just because the truck can do it, the tires will be the weak link.
Like on a turbo cat. 175 hp is great, til the belt shreds & youre left out in the cold.