non run flats tyre pressures

[jayxx83]

I use 35 psi front and 33 psi rear on a mcs with 17" tyres. Whether the tyre is a run flat or not makes no difference in my opinion. The pressure is the same regardless. The stiffer sidewall is just a characteristic of the runflat and a harsh ride the result of that stiff sidewall.

I would not try to replicate this in a normal tyre as you may suffer a blowout at high speeds. You are also likely to wear out the tread in the middle. You dont see other manufacturers recommending anything over 40 psi for their cars fitted with normal tyres.

The softer sidewall will mean, if you have adjustable shockers, that you can turn up the damping rates to compensate for the extra roll the softer sidewall generates, not cramming more pressure into them to make it a saftey hazard.

[Garyhalliwell]

Hi there, I am running 215/35ZR18 84W NANKANG ULTRA SPORT NS-II tyres on JCW wheels my clubman. I have no idea what the pressures are front or rear. Any one able to help?

[frashed]

I've been running at 2.6 bar and really happy with it. I'll stick to this.

[jlove]

Sort-of the same old question but can anyone with experience recommend pressures for my JCW with 205/45 17 Pirelli PZeroes, non run-flat; specifically for track day running?

Pirelli don't seem to have a view but I've got Vredestein Ultracs on another Mini and they actually recommend 3.0 bar F and 2.7 bar R, that's 44/40, in old money, by my calculation. For track running, I'm normally inclined to increase the fronts and lower the rears a bit.

Any opinions?

[beken]

I'm running 38psi front and 34psi in the back. I came to that conclusion based on tire wear pattern. If too high, the center groove wears faster, if underinflated, the side blocks wear faster. Other factors to be considered that are affected by tire pressure, rolling resistance, traction and noise. The wider the tire you have, the noisier it will be as the tire wears, especially if your tread blocks create a resonance while rolling at certain speeds.

Tire pressure will be different for almost every tire model and how you use your car. That's one of the reasons I hate shopping tires.

For track day running, people I know would use chalk and mark their tires with a tread cross section and then adjust pressure based on the markings. I suspect tire pressures would be higher than normal street use.