jimlab

I just read a couple threads in which the stock tires were listed as having a load index of 92, and it was advised not to use a tire with a load rating lower than stock...

However in those same threads, P255/35-18s were recommended, and this size was also recently recommended to me in a private message on tire and wheel selection for my car.

The problem is that the Bridgestone S03 Pole Position P255/35-18 is has an index of 90, or 1,323 lbs. If stock is 92, or 1,389 lbs., then 1,323 is close, but obviously does not meet or exceed the stock rating.

Thinking maybe this was a misprint on the Bridgestone site, I decided to check a few other manufacturers...

Toyo Proxes T1-S, P255/35-18 = 90 / 1,323 lbs.
Nitto NT-555, P255/35-18 = 90 / 1,323 lbs.
Dunlop SP-9000, P255/35-18 = 90 / 1,323 lbs.
etc.

So now it's obvious there's a conspiracy, or more likely, just a formula for calculating tire load rating, and the P255/35-18 is 1,323 lbs. no matter who manufacturers it.

So why are two people who recommend not using a tire rated lower than the stock tires also recommending the P255/35-18? Confusing? You betcha.

Anyone have an answer for this?

jimlab

Of course one solution is to simply run a P265/35-18 instead. The load index is 93 (1,433 lbs.) and the road gods are appeased.

On an 18x9" wheel (although I could probably go 9.5"), that shouldn't be a problem, and it's only ~0.27" taller than the P255. I don't think an eighth of an inch or so all the way around is going to make much of a difference. I doubt you could tell the two tires apart from the side, without reading the lettering.

Anyone think this is a bad idea?