what psi

[Keyfoo]

ok this maybe a dumb question but , I got simitomo srixon4 for my L- type, rated a 130mph, thought It was a good deal at 45 per tire and have a great ride. but they can take up to 51psi. most tires Ive had were up to 35. do I run on standard 26/27
or higher?

[lechner]

Depends on a lot. You will get better gas mileage at higher psi, but the ride will suck, traction will suffer, and the tires will wear in the middle. The 'proper' answer is to always follow the car manufacturers suggested pressure because it matches the weight being placed on the tires and maintains the most even contact patch.
But I don't think it hurts to deviate at times. I use 35-38 psi on long highway trips to conserve gas. If I'm cruising the town and maybe doing a little stoplight racing, I lower the pressure to 22 psi (also when taking lots of dirt roads). Most of the time, I run 28-32 psi. I don't know that these are the best numbers for you to use, though, they are just what I happen to use. All newer radials are capable of higher psi than we need.

[CJSREDPRA]

I usually stay w/ 30 psi (cold, it's 32 psi when warm/hot).

27 psi is borderline okay for the stock 225/60 tires. Anything below that, you start getting underinflation wear.

Anything over 35 psi for long periods, you WILL start to get overinflation wear. Ask how I know..... :D Thus the reason why I keep them @ 30.

[straight-six]

I too stay around 30. unless it's snowing, then i drop it to 18 or so.

[Tire Shredder]

My MotoMaster Predator 215/60s have a max pressure rating of 35 psi. I've been keeping them all at 35.0 (digtal tire gauge...sooo sweet) most of my driving is done on trips that are between 20 and 30 minutes at about 100km/h. should I keep with this pressure or do you guys have a better suggestion. Also, for those tires, what pressure should I have in them for long trips?

[lechner]

If they are rated 35 max I wouldn't go over that even for long highway trips. If you have had them long enough for them to start to show a little wear, is the wear more in the center of the tread or the edges of the tread? Usually if left at 35 psi on our cars the middle of the tread will wear before the outside edges, and if this is the case you need to lower the pressure so the tires will wear even (if they are already wearing even, don't worry about it). Basically you want your average pressure to be around 30 psi. If you go higher at times and lower at times, you still want to average 30.

[Tire Shredder]

have had the car for over a year and notice no abnormal wear but I haven't noticed the tires wear at all. I swear these tires have a treadwear rating of 800000 :). you can sit and burn them for a considerable amount of time and they look no worse for wear lol.

I'll lower them down to aorund 30 or 32 tomorrow and see how it goes. The key is that they are all equal pressures.

[StanS]

Keyfoo, u could start a war with that question, lol. It depends on the tire. Here's the info on three sets of tires that I've had. Gislavid (Swedish), stock size 125Kmi with even treadwear till the tread wore out with normal driving on 84 Auto (32psi). Michelin pilots, stock size, 84 manual, used 1/2 the tread in 60-70Kmi, spirited driving, even wear, 36 or 38 psi. Falken 225/16/V40, 30Kmi, 1/3 tread used, even treadwear, spirited driving, 40/38 psi f/r. Last 2 tire types have slight rear inside wear due to excess rear camber.

[Keyfoo]

well my supra is a l type 195/70-14 just never seen 51 psi marked on tires, usally 35max. my glove box says 27psi.

but to add another bullit to the war. lol Dose anyone use nitrogen to fill tires, Ive heard it dosent expand like air when tires heat up and cosco will fill your tires with this.

ps tks for the info.