Tires do more than carry weight, which is their main job.
Accelerating, braking, turning, cushioning, and cornering. All at low speed, up to their speed rating.
Their application also varies and why there are different classifications.
ST = Trailer
P = Passenger
LT = Light truck
Commercial = Semi’s and normally in half inch dia sizes
Off Road = Those on HUGE truck. Wheel dia measured in feet, not inches
Am sure there are other classifications. Like airplane, farm, etc.
The old way was to rate a tire by its actual number of sidewall plus. Meaning an “E” tire actually had 10 plays of cloth (normally cotton, IIRC)
Newer way is with a number code that references a chart listing what that rating is.
Now, OEMs mostly have both letter and numeric code on LT sidewalls and charts.
As the actual number of sidewall plys run from one to two layers of fabric. One of our resident tire engineers might come along to provide more info & details
I do know that serious off roading would shread most P class tire whe aired down. While same size LT would not be harmed, other than bruises. But, that was a couple decades ago when still hardcore off-roader. Material science and production methodology have come a ways since then.
To the OP...careful shopping for the same sized tire with the highest load rating. As some stores will only show you what they sell. Even though another brand might have a higher rating.
Do your research and make sure your wheels are also rated for MORE than the tire’s rating (personal preference), as the tire has more compliance than metal wheel will have.
