I've got a relatively new set of Michelin PS2's on my 951. For the first time I noticed a couple tires low and fired up the compressor to air them up...

There's no guidance on recommended pressure on the tire - just says 51PSI max. For general road driving, what do you guys think? I went with 32PSI...

 

that should be good.

 

street tire pressure should be the same, regardless of what tire it is. the tire patch at a "standing" is dictated more by the weight on that tire and the tire pressure, not really by the compound or the sidewall height.

 

If you're talking cold pressure, I usually set all 4 tires up at about 35lbs prior to a DE....but I'll let them be slightly lower for street driving....so 32 should be fine.

 

Every tire and every car are going to be different.

Different brands, sizes and compounds will flex differently. Not to mention that not every 951 and owner weighs the same.


Here is a very quick and easy way to figure out the proper tire pressure for YOUR car and YOUR tires.


Drive the car to down the road a few miles, to work, home gas station etc.

When you get out touch the tires in 3 spots. Inner third, outer third and center third.

A properly aligned and inflated car should have an equal temp on a three areas.

If the center is hotter than the edges you have too much air pressure.

If the outer edges are warmer than the center you are too low.

Inner or outer edge significantly warmer than the rest of the tire could indicated an alignment problem.

You can use this method any time, any where with no chalk or laser temp gauges. You will be able to adjust it enough with just your hand.

You can also easily adjust your air pressure for varying loads. Load the car up with a passenger and a bunch of luggage. Simply check the temsps at your first gas stop and adjust the pressure for that trip.

I have used this method for decades and get very impressive life out of tires doing it.


Good luck.

 

Good advice guys, i think he should start at 36 to 38 pounds... not less than that. at 32 pounds, the tires will get too hot at over 70 mph. you can pull into a rest area and it will be noticable. at 36 pounds plus the tires will require some very high speeds before getting very warm.

i once had my Dunlops at 32 pounds and did a 125mph pass on for about a minute on a good stretch of straight on I-29 in western Missouri... twas a freezing cold night, maybe 18 degrees -- just to see how hot they could get... won't be doing that again.

i know it's contrarian to be running high pressure in any street tires. but quite frankly that is what they are designed for -- especially considering you are not overloading them with a heavy SUV, which the tires are designed to handle in a worst case scenario... so don't be shy about 38 or even 40 pounds for the street. that is the pressure that will keep you from destroying them.

 

No way. Any pressure above what's needed to keep the tread flat under the load will just wear out the center of the tread. It shouldn't take more than 32 to achieve full contact.

The max pressure shown on the sidewall is solely for load rating purposes.

 

hmmm... my tires have worn perfectly for the past 4-5 years running 36-38 pounds without any issues.

 

Here's what my backs look like cold inflated to 32PSI. I'll do the hand/warm test next time I take a trip...

 

Those look fine, maybe a little too much, you can see the outer 1/2" or so isn't touching, but that could also be due to camber.