hi Guys and girls,
I have a question. I recently bought a Honda S2000. a problem with that is that the standard wheels are not underneath it. the wheels that are now under it are: 225/35 ZR18 87Y XL. the standard tire pressure of the OEM wheels is 2.2 but I have no idea what tire pressure I should keep with these wheels that are now underneath it. I am now using 2.3 on all 4 tires. Do you have any suggestions or ideas what the best tire pressure is in this case for safe and sporty driving.

regards,

luka

 

Type of tire and usage would help

 

Pirelli Pzero Nero GT 225/35 ZR18 87Y XL summer tires. And i use them daily

 

Go by door jamb sticker. But really, you're gonna be fine with ~2.0 - 2.4 bar, or even a wider range than that.

 

Seems like all the OEM size tires for the S2000 have a Load Index of 91 (1356lbs/615kg) per tire. An Index of 87 is only rated as 1201lbs/545kg).

My guess is the lower rated tire will need a couple psi more pressure to perform well so 2.3bar is as good a guess as any. Keep an eye on tread wear in a few months. It's possible to check the contact patch by driving thru a film of wet pavement and observing the wet print and noting if it's even across the tread.

-- Chuck

 

Worth noting that static load on an S2000 tire is ~750 lb. so load rating is pretty much not an issue.

Yup.

With any camber at all, it won't be "even across the tread". Also IMO the "rules" about tire pressure vs. wear pattern are a lot less relevant for radial tires than bias-ply.

2.0 to 2.4 bar (30-35psi) range is gonna be fine, I'd start in the middle of that. I would not "chase" pressures outside of that range based on wear patterns which are often more dictated by toe settings. Which should be set nearest to zero front and rear for best tire life and hanlding. IMO...

 

Not a question of supporting the weight of the car as passenger car tires can always support more than the car weighs. Without getting out of my chair I'm guessing the OEM tires are rated at a maximum of 1356lbs at 50psi (fifty) yet we run them at 32psi for a compliant ride and getting the contact patch where it should be.

Anyway what's a couple psi between friends?

-- Chuck

 

S2k peeps should pretty much *never* go by the sidewall pressure! It's only there to show how high you can go in case you are supporting a lot of weight for a given tire size. Pretty much never happens for "normal" cars and definitely not for sports cars!
Yeah, it's not a huge deal with radials, but I hate to see people chasing psi based on things like chalk marks, how close the wear pattern is to those little sidewall arrow markers (which are only there to point to the treadwear indicators) or other "indicators" of dubious merit! Door jamb recommended pressures are always gonna be well within the range of pressures that will work fine. If it feels to soft add a couple of psi. Too hard, take out a couple.

 

Agreed on "door jam" pressures when dealing with standard tires. Or not straying too from them.

-- Chuc

 

Thank you Guys!