packohotdogs

Hey Everyone

Those of you with 245/40R18 tires, what PSI do you inflate to?

I am currently at 34psi, but if I inflate to 37-38psi will I cup the tires?

csmeance

I find that the optimal pressure is 35 PSI COLD for most cars and alignment settings.

Make sure that you fill up your tires to around 40PSI and let the car sit overnight. Then in the morning let out some air to 37 or your desired PSI. I think 38 is going to be a bit to high and will cause wear on the center of the tread. To low and you cause wear on the outside edges (both) on the tire.

Cupping is due to a bad alignment on your car or bad suspension components.

Ricky Pounds

35!

Turbonut

iTrader: (1)

The load rating of the tire should also be taken into consideration when air pressure is adjusted as in this size, there are load ranges, 93 and 97 (XL-extra load).

practice89

iTrader: (1)

not to thread jack but what about 235/40/18? and if brand matters, i have hankook v12

al.c

I'm running on 35psi all around. But factory is 35 in the front and 32 in the rears.

AcuraIntegTL

I currently run 37PSI in front and 35PSI in back, tires warmed up. I'm getting the same size Hankook v12 tires mounted today and plan on running the same PSI.

SweetJazz

There is no way you should be using less than 37 psig for these tires. I will typically inflate to 40 psig in front and 37-38 psig in the rear for a FWD car (cold measurement). These tires will usually have a max pressure rating around 50+ psig so 40 psig cold is not an issue when warmed up to around 45 psig. Never had an issue with cupping or wear and I am fanatical about maintaining tire pressure. IMO, 35 pisg will provide little sidewall support for a low profile tire especially if you like the twisties. 35 psig will also make your tire look like it is losing air.