I just checked my tire pressure today and found that I had only 24psi in all four of my tires. I've got 15" Pirelli runflats on (OEM). Door sticker says 30psi, so obviously they are significantly underinflated. My question is whether my runflats have been harmed by running at this low tire pressure. I'm worried about damage to the sidewalls. Anyone have experience or knowledge with this type of problem?

Thanks!

 

15" OE runflats? I don't think so.

 

Only the 16" and 17" OEM tires are run-flat. The 15's on the MC are regular tires (non run-flat)

 

How long did you run them at 24psi?

 

either way, if it was only a month or two without lots of mileage and/or long distance travel, it is probably OK

 

Ummm....I ran my runflats at 0 psi for OVER A YEAR. You have nothing to worry about...especially from 6 psi.

 

Now, how and why did you do that?

 

I had a roofing nail or some wierd contraption in it and never got them fixed. Then I went to 18's. Most times speeds were in the triple digits and the tires never faltered.

 

I think you are OK. Check the tire treadwear.

Running low pressures, you get poorer gas mileage and less contact to the road with wet conditions. You get more wear on the outer edges of the tires but I guess you liked the cushy ride quality- like a limo. And you thought that was normal.

Check your temperatures in the morning when the tires are cold. If you check them when at the hotest time in the day then recheck in the coldest time the tire temp drop causes a loss in pressure drop as well. Put in about 32 psi in the morning and you should be fine.

 

my sister has 16" runflats. The cold weather came... didn't check them and ran them at 16-18psi for about a month or two. After realizing this I correcting the pressure.
One month later the front right tire went flat. Took it to Goodyear dealer to repair. After looking at it you could see it had a 1" rip in the inside sidewall of the tire. They said the tire was run underinflated and killed the sidewall. Had to buy new one.
Expensive lesson for her.

 

16 psi is a little too low for a month or two especially driving around town or on highways. I guess that was thoroughly testing the runflats in an extended way.

Time to change to non runflats and check your tire pressures. Hey, you wouldn't want to ride a bicycle with flat tires!

You could always do this-
From:
www.aa1car.com/library/ tire_monitors.htm
INSTALLING AN AFTERMARKET TIRE PRESSURE MONITOR

"One way to upgrade driving safety is to install an aftermarket tire pressure monitoring system. The cheapest type (under $15) are simple spring-loaded "safety caps" that fit on the existing valve stems. The safety caps have a window that show a color indicator inside. Green means the tires are okay (30 to 32 psi), yellow shows if pressure drops four pounds, and red shows if pressure drops 10 or more pounds. The only drawback with this system is that it requires the driver to visually inspect the tires. There is no warning light or message inside the vehicle -- which means if a tire loses pressure while driving you won't know it until it goes flat."

 

Thanks for all the info. Due to the comments posted, I have now discovered I do not have runflats. I was told by the dealers that they were runflats, and I took that at face value. The tires are actually Pirelli P3000E, and as far as I can tell, they are certainly not runflats. I actually didn't want runflats, so that's okay...but I do feel a little stupid for thinking I had runflats for the last six months. Oh well. I guess it means the tires are probably okay (correctly inflated now, and I just got a fabulous digital tire pressure gauge as a stocking stuffer, so I'll be checking them more frequently now).

Thanks for the help!

 

No sweat - I HAVE runflats and swore for a couple of months that I did NOT have them because my MA told me that. And I was too much of a nimrod to actually READ the sidewall on the tire... So maybe you and I can start a club or something... We could print up badges with the side view of a tire and a big question mark in the middle...

 

Hey Paul,

Thanks for making me not feel quite so dumb!

 

I checked mine this morning and they each had a different pressure....anywhere from 21 psi to 26 psi. It has been sitting in the garage for over a month so I guess that is to be expected. I think your runflats will be fine.

 

It's probably been said here before, but I think it bears repeating in this thread: if you live in a place where you actually have seasons, check your tire pressures when the wether turns noticeably colder. Cold air will condense, so to speak, and tire pressures will drop more than normal. Of course, you should check your tire pressures regularly, anyway, but this for people who don't do it _as_ regularly, WTM.