Quote:
Originally Posted by Tireman9
You do realize that "Ply" went out in the 60's with the switch to higher strength Nylon, Polyester and finally to Steel in "Commercial grade" tires. If you read the tire sidewall you can learn the actual number of layers aka ply in your tires.
Load Range G or LR-G is the modern and correct term even though some tire companies use the "ply" designation as some customers don't understand we are really talking about the ability to retain the inflation pressure and it's the inflation pressure that supports the load not the tire itself. At least for 95% of the load. Else why Load & Inflation charts?
I have never seen a Ply vs load chart.  |
Plyrating is commenly used in Europe, only when also for american market , loadranche is given.
Sometimes even both.
And ofcource it has nowadays little to do with the real mumber of plies anymore.
Here a incomplete list I made
Loadrange/ psi/ plyrating / psi
LrB/ 35 psi/ 4ply/ 36 psi exeptions to lower
LRC/ 50PSI/ 6PLY/ 55PSI has given many conversion problems in the past, so to low pressure because lrc goes from lower AT pressure.
LRD/65PSI/8PLY/ 65PSI ( 69PSI exeption but also 425 kPa= 61 psi )
LRE/ 80 PSI/ 10 PLY/ 80 PSI ( exeptions 77 and 87 psi)
So what counts is what is written behind AT in " maximum load xxxxlbs/kg AT yyy psi/ kPa ( cold)
So if you find that, forget the loadrange/plyrating, and find a pressure/ loadcapacity- list for that yyy psi and xxxx lbs/ kg.