Hello to the Forum,

Bought a 2001 convertible a couple of years ago and have been reading this site for some time. You guys/gals are great---I've learned a bunch and used your advice for a recent purchase of some new tires. I bought 4 new Michelin Pilot Sports not run flats and the GM air compressor. Installed last week and need some advice. The tires list 51 max psi and my tire installer was reluctant to go much below that level. One issue that this created is that my high pressure warning light is on all of the time. My question: I realize that the 51 recommendation is maximum---how low do you/ can you run these tires and not effect safety? Also, will running the pressure too low cause abnormal wear patterns? Any other advice would be greatly appreciated.

 

Your tire installer is a moron and you should stay away from him! Depending on weather conditions, road conditions and driving style you should be running in the 30-35 PSI range.

 

If you are running anywhere near stock tire sizes, you need to be right at 30psi. Most run right there, a few a pound or two higher and maybe some a pound or two lower.

If you run at 50+psi you will wear the center out of your tires in no time flat, not to mention the ROUGH ride you will encounter.

30PSI

 

The door plaque says 30 PSI cold....All around. That is GM's recommendation for any tire regardless of what the tire max pressure is.
This time of year and in the fall I run at 30. When the summer gets hot, the asphalt heats up, I will drop to 28 psi all around.

 

or else looking for repeat business from you in very short order!

A little education from the folks at Tire Rack will go a long way:
http://www.tirerack.com/about/techcenter.jsp

 

According to your owners manual which is a much greater authority than a tire monkey it's 30 psi cold.

 

51 PSI?@#%%?

 

If 50 psi is the max pressure, all it means is that is the most pressure the manufacturer says the tire will safely hold. Has nuthin to do with what you should be running, unless your car door sticker or owners manual recommend a tire pressure higher than the max the tire manufacturer recommends. In that case you've got the wrong tire on your car, which isn't the case here. I'd set them at 30-32 psi when cold, preferably after sitting overnight and then closely watch their wear patterns.

 

WOW! Don't sugar coat it guys! Let loose and tell him how you feel, don't hold back!

The pressure listed on sidewall is the maximum pressure for the tire - not necessarily the correct pressure for the vehicle.

The tire manufacturer has no way to know upon which vehicle the tires will be installed, so they list the maximum pressure the tires can be run.

The vehicle's engineers determine what pressure will offer the compromise of best ride, handling and wear characteristics. Obviously vehicles have different gross weight, and that compromise is different for each vehicle. This is why each manufacturer places a tire placard on the door or jamb on the driver's side of the car. But understand that the number is a recommendation of cold tire pressures - driving style and climate have an effect of what will work best.

Living in the desert southwest like I do means that my tires are exposed to higher road surface temperatures and ambient temperatures, versus living in the Pacific northwest for example. Also - summer temperatures are higher, so the air in the tire expands more than it does in the winter.

Through experience, I have found that my optimal temperature for tread life, ride and handling is about 32psi hot - and so to achieve that I have to vary the inflation a few pounds lower in summer and a few pounds higher in winter. I run about 26 pounds cold in summer and about 29 pounds in winter. The key is to keep an eye on the inflation and make sure that alignment is within specs.

If you choose to not pay close attention - then by all means follow the 30psi cold recommendation and you will be fine....regardless of what tire you have on the car. Hope that helps...

 

Thanks for the candid feedback.

30 it is.....................................

 

Put 30 psi cold in the tires - that's the recommended tire pressure as listed on the driver's door decal.

 

30 to 35psi I check and put in 30 when cold. Will get around 35 after driving for a while

 

We have a winner!

Always refer to the vehicle manufacturer recommended pressure on the door label.

 

many tire installers fill the tire to the recommended max to help seal the tire bead. after 24 hrs drop the pressure to the recommended levels.