Ok, friend just purchased a new set of BFG A/Ts that were supposed to have 10 ply rating, but the guy installing em said he thought they had 6. So we thought we would compare to some other BFG A/Ts. we have mine, a friend who supposedly had 10 ply, and the new set that was purchased.

Mine: Ply: 3 Poly. + 2 Steel (mine came on my vehicle so not sure)
Friend: Ply: 3 Poly. +2 Steel + 2 Nylon (10 ply?)
New: Ply: 3Poly. + 2 Steel + 1 Nylon (6 ply?)

any ideas how to decode the ply ratings?

 

Ply ratings are just that "ratings". They do not necessarily mean the tire has that number of plies.
Most newer tires have the rating on the sidewall ie. Load range B=2 ply rating, LR-C=6 ply rating, D=8 ply rating, E=10 and so on.

 

Load range C is rated 6 ply, D is 8, E is 10. No load range LTs are 4.

 

so when you order a tire do you get to pick the load rating? or is it just based on tire size?

 

i believe you can get the same size tire in different load ratings, but it's all subject to what the manufacturers offer. seems like the "popular" tires usually come in one size/load rating combo.

 

Some tires come in different load ratings for the same size, but most of them don't, the load ranges go up with bigger sizes.

 

Usually it has more to do with the size rim. For eaxample, 'D' rated tires are very common for 16" rims because trucks tend to run 16 inchers...

EDIT: BTW, if you look around on Discount Tire's Website, they have tires for 16" rims, and in some cases you can buy a 'C' rated or 'D' rated tire, the 'D' rated being more expensive...

Similarly, you can find ridiculous load ratings (E, F?, G?) for 19.5" rims, a common size on HD trucks I think.

A friend of mine has an explorer with 41" tires (yes it's huge, D60 front D70 back), they are military Michelin XL's, rated at (I think) 'G' or 'H' for 20" rims, he got the USA 6x6 beadlocks and they are SICK The sidewall of the tires are about an inch thick! He's planning to be able to offroad the thing at 0 psi

 

And just to clerify one more thing... Is ply rating directly related to hardness of the tire? or is it just related to the thickness?

In other words would a "D" rating have longer tread life than a "C" rated?

 

It only applies to load carrying capacity.

 

Load carrying capacity and it is a little harder to push nails through but wear out same speed as most.

 

All about reading tire sidewalls:
http://www.4crawler.com/Diesel/Tires.shtml#SIDEWALL

 

I am pretty sure each manuf has a different definition of "ply" They all differ in thickness. BFG ATs and MTs are incredibly strong tires. they use a lot of layers. Call michelin, they may have a more precise answer for you.

 

So,do D load rated BFGs have more sidewall protection than the D rated Nittos? That seems to be the bigger argument for BFGs is their sidewall thickness.

 

I think the BFGs do have more layers of the string like molds than the Nittos. I dont think there is a tire out there stronger than the BFGs

 

I believe the "ply rating" doesn't have to do with the sidewalls, it has to do with the circumferential tread plies. Every tire has the plies listed on the sidewall, it will have the number of plies for the tread and for the sidewall. I believe "ply rating" does not directly correspond with actual number of plies, but is a reference to the load carrying capability.

 

the tire ply is the whole tire. THere is a ply on top of the tire as well as a ply on the side. THe ones on the side are usually nylon and wrap around the whole tire (top and sides). THere is also another ply that goes on top of the tire.. The ply rating is the number of plies that the tire has.

 

Matt,

The ply rating has nothing to do w/ the actual number of plies used in the tire. I have seen many a "6 ply" tire that only has four actual plies.

This is taken from Tire Rack's website and it does a good job of explaining the subject.

The load range or ply rating branded on a tire's sidewall helps identify its strength and ability to contain air pressure. While specific load ranges are assigned to passenger tires, load ranges are identified in ascending alphabetical order for light truck tires (the further along the letter is in the alphabet, the stronger the tire and the greater amount of air pressure it can withstand and load it can carry). Before load ranges were adopted, ply ratings were used to identify the relative strength of light truck tires with higher numerical values assigned to tires featuring stronger, heavier duty constructions.

Today's load range/ply ratings do not count the actual number of body ply layers found inside the tire, but indicate an equivalent strength based on early bias ply tires. Most radial passenger tires have one or two body plies, and light truck tires, even those with heavy duty ratings (10-, 12- or 14-ply rated), actually have only two or three fabric body plies, or one steel ply.

http://www.tiresafety.com/construction.asp

 

I was referring to the infobox found on the tire. They have stamped on there how many plys the tire is.