Tyre rating 112S vs 121S

[Wil Senior Member Find all posts View Profile Close Wil]

Rating for a 112S tyre is 1120kg

Rating for a 121S tyre is 1450kg

Price for these rating tyres is comparable at the moment with only a couple of dollars difference. Obviously both ratings comfortably cover the weight of a prado, so what is the tradeoff?

Will the 112S bag out better at lower pressures whilst the 121S have better puncture resistance assuming higher load rating means more ply's?

Other pro's and con's

I am looking at buying on line so noone to ask my stupid questions to.

[Guest Close Guest]

Higher load rating is from more plies/stronger construction. It can still bag out but with less air pressure. Better to get the higher load rated tyre if you're going offroad more than just a mum's taxi.

[Wil Senior Member Find all posts View Profile Close Wil]

My thinking was that the higher load rating would have thicker side walls and this would mean more heat and bending stresses when at reduced pressures. These tyres will see a trip from perth to the cape which is lots of dirt at lower pressures meaning lots of heat and flexing sidewalls.

The engineer in me says dont over specify, the bogan in me says more is more.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

How low do you propose to go? Most outback dirt roads are fine at about 28 psi and sitting on about 80- 90 kph. They wont overheat at those settings. On really rough ,low speed low pressure stuff the same applies - less speed = less heat. For a trip like that a good AT tyre is a no brainer, especially if you are up for new tyres anyway. Not too many AT tyres fail in the outback at those pressures but plenty of passenger spec. tyres do.