I noticed that when cornering (not that hard!!) that my tires squealed. I immediately suspected low pressure.

I checked them this morning after a 40 mile highway speeds ride (warm) and they were all sitting at 28 to 29 PSI... Seemed LOW to me when the sidewall pressure recommends a MAX of 51 PSI and they were "warm."

I've just let them sit in 50 degree weather for about 45 minutes and now I'm going to increse the pressure to ~38 PSI. I'll check the door panel to be sure... My question is at what pressure do you run your All Season run flats?

I'll be switching to steel wheel/Blizzaks in a month or so BTW...

TIA,

Dave

 

35 - 38.

®

 

Same here. When the tires are warm, mine measured out at just under 30 lbs too.

 

The door of my car says to do 38PSI for all 4 tires on the runflats. If they go below this you will notice the ride get softer

 

I increased my pressure to 38 PSI with the gas station built on gauge (you know those big brass pressure valves that pop out to the indicated pressure) and then I checked it later with my handy-dandy DIAL gauge (0 - 100 PSI) and it read 35 PSI! What to believe?? So I ran to "Autozone" and got myself a 0 - 60 PSI gauge ($7.95) and checked it and it, too, read 35 PSI. I'll be topping off to 38 PSI when I leave again. I'm tending to believe the two personal gauges over the gas station brass thingy.

Well I've got a 66.3 % chance that I'm right anyway, lol...

Thanks for your replies.

Dave

 

Make sure you get a decent pressure guage with a needle, not one of those stupid ones with the plastic piece that pops out from the end. Too important an item to be cheap on.

 

You rather trust a new gauge or one that has been dropped and run over a million times? BTW dropping a dial gauge (or clicky torque wrench) just once destroys its calibration-the pencil gauges (and beam-type torque wrenches) are far more rugged. And gas station gauges are notorious for being way off, so 3 psi off is pretty good.

 

I run 40 psi in mine... but then I like 'em super-stiff... better for cornering that way. I don't care about the harsher ride.

 

Somebody tell the member from Brooklyn who recently griped that his 17" SSR Comps got bent. He was running 32-33 lbs. because the ride was too hard with more air...

 

But at what point does the tire start to become deformed from the additional pressure? If you laid a ruler across the tire, from sidewall to sidewall, it should be in contact with the tread all the way across. Too much pressure and the ruler will rock like a teeter totter; not enough, and there will be a gap between the ruler and the tire in the middle. Either one causes extra wear and a reduced contact patch. I'm not saying 40's going to cause the teeter totter effect, but at what point does that happen?

I try to keep mine right at 38, but it's a constant struggle; they're always losing pressure, *way* faster than standard tires do, in my experience. Within a week, I bet I lose 5 psi per tire...

I think you wasted eight bucks on that pencil-style gauge. I've read that they're crap. Supposedly the best kind are the dial-type gauges. I've got a digital one, but I'm not sure I trust it, either...

 

Tell him what?

 

Tell him he was running about 5 lbs. low - when I tried to say so, several people chimed in about how they've never had a problem with 17" wheels at 33 lbs, `cause it says so on the door sticker...

 

just set your tirepressure in the morning in a garage at 35psi-36psi for your cooler temps.

air expands contracts 1psi per 10F change.

 

>> 33Lbs each tire checked when tire is cold. Inside the door on my Cooper it says 33Lbs.

>> Try that and see how you like it and if it does not feel right add a Lb the next time the tires are cold. Go from there.:smile: I would not go any softer.

MINIMAX 1

 

Inside the door on my 06 MCS says 35 psi all around. Has this changed from past years, and should I go by what they say or add some more air? My tires are the 17" all seasons, I also have a set of 17" Pirelli Snowports (non-runflat).

 

Interesting..did your car come with the all season tires or summer tires?

 

I got All-Season RFs and the sticker on the door says 35 psi. I got all four pumped up to 36psi