My manual says (if I can possibly figure out what that grid means) between 30 and 35; when I picked the car up from the dealer, he had it at 37 cold (by my digital gauge). I decreased air pressure to 33, but really like the handling and ride at 37. What are others with the 15 inch tires keeping their pressure at?
Thanks!

 

Cheers!
Clover

 

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>>Cheers!
>>Clover
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Clover,
Thanks! That's interesting. My front left was a couple of lbs higher too. Hmmm! That's it-- the middle button on the left back side of the steering wheel is to even the air pressure. I will have to check tomorrow.
I hope you are thrilled with yours. I'm really surprised by how much I enjoy this car. It seems that each day I enjoy it more.
Steve

 

Steve, Oh I love MINIclo! I can't really believe she's mine! I keep thinking that I have to give her back...that she's a rental or something!

 

I was always under the impression that the manufacturer's suggested tire pressures were pretty worthless - they are seeking:a) "ride quality", b) tire longevity
and NOT handling. The max pressure on the tires is true max and the minimum pressure can only be determined by monitoring the tire for signs of underinflation (i.e. loss of steering precision, flexed sidewall, loss of cornering stability).

Typically, participants of drivers schools/autocross/high performance track driving sessions are told to pump up your tires 10+psi more than manufacturer recommended on higher profile (i.e. smaller rim size & thicker tire) tires to ensure the tire will take the abuse of a drivering school and stay on the rim. This is fine for short period and used only as a starting point - each driver has thier own preferences.

Personally - for street driving I tend to use manufacturer recommended as a one data point but it really comes down to the feel of the car at speed and cornering because I'm not worried about tire life and more interested in handling (but running higher pressure implies harsher ride and potentially more easily damaging tire/rim on potholes - again, I can live with it).

My spin on inflation is that under inflation = bad, overinflation (to a point) = good. So, if 37 'feels' better/right why wouldn't you run at 37 if it's under the max stamped on the tire?

-Dave

 

I tend to run a few lbs of pressure under whatever the maximum cold pressure on the tire is. I run the 44lb tires on my bonne at 40 and the 50 lb tires on my old jeep were normaly just under 45 unless I was hauling a heavy load then I put them up to 50.

I would suggest putting the tires to a couple pounds under their max cold rating and just see how they feel. Adjust acordingly from their but just remember to never inflate them to over their max cold rating.

I always laughed at the new Ford F-150s and Explorers that come in and the suggested air pressure on the door is around 29 in the front and 31 in the rear. That is a freaking joke and I would not be surprised if those ultra low pressures did not have something to do with the tire faliures on explorers. Having 29-31 lbs of pressure on the tires of a truck that's empty weight is above 4000 lbs cannot be safe.

 

>>I always laughed at the new Ford F-150s and Explorers that come in and the suggested air pressure on the door is around 29 in the front and 31 in the rear. That is a freaking joke and I would not be surprised if those ultra low pressures did not have something to do with the tire faliures on explorers. Having 29-31 lbs of pressure on the tires of a truck that's empty weight is above 4000 lbs cannot be safe.


I wouldn't doubt it for a second either... but they have the pressure so low because the suspension cannot handle maneuvers at speed, so they run the tires really soft so they can take the body roll... not the best design, I would think...

Rocketboy_X

 

The whole exploder fiasco was a huge list of contributing factors where the abscence of one might have stopped the problem.

The engineers originaly wanted to put 225/70 R15 or 215/70 R 15 tires on the exploder but the marketing people vetoed them. They said that they needed to put on 235/75 R 15 tires so the truck would have the right 4WD stance. During testing the Exploder handled much better and was much more stable with the smaller tires but the larger ones were put on anyway.

You know there are serious problems at a company when marketing people are overriding engineers in relation to a safety issue.