i have a strange issue , setting cold tire pressure exactly the same right to left tires per axle ( 35 psi front / 40 psi rear ) , when check the hot pressure after street and highway high speed driving (onboard driver only) , the left tire is always about 1,5 psi high more than the right tire ( i have about 40 both right and left Front ,45 rear right and 46.5 rear left .

This "hot pressure" difference left to right happens on the rear axle only , since on the front the pressure increase the same for both left and right.
Since before check the hot pressure i drive the car most of time on the straight line , apparently there is no reason why the temperature so the pressure increase more on the left than on the right rear tire.
Since the alignement is ok and tires are brand new PS2 , i thought the only reason maybe the driver weight on the left side ( unfortunately 100 Kg ) can affect rear left tire temperature / pressure increase of 1,5 PSI more than right ?

Any one has any Idea or experience in this ?

Many thanks and so sorry for my english !

 

Check the temperatures with a prymometer or temp gun. it could be a dragging brake or wheel bearing going bad which is creating additional heat and therefore tire pressure.

Also, check the alignment on the hot wheel. if it has too much toe in/out, it would create drag and therefore heat and pressure.

 

i have done the test also today and the result is the same left rear is 1 / 1.5 psi more than right rear !
So the temperature of the left tire could be 10 celsius desgree more than right tire !
But could not be also my weight since i drive the car without passengers that increase weight distribution on the left side of the car so more stress / heat on the left rear tire when accelerating ?

 

In any case at the moment i have drop 1 psi the pressure of the left rear so that if not the temperature , the pressure will be the same left / right at least

 

In any case at the moment i have drop 1 psi the pressure of the left rear so that if not the temperature , the hot pressure will be the same left / right at least

 

What I recall from my (brief) time with my 08 Cayman S and its TPMS is tire pressure changes quite a bit as the car is driven. It was really an eye opener to note how dynamic tire pressures are when the car is being used.

Driver weight didn't seem to play a role. Side loads, turning, was the biggest factor in pressure changes is what I recall.

In your car's case I would suspect tire/wheel alignment. Misalignment can cut tire life in half and this means the tire is experiencing more friction and this means more heat.

(A day after picking up my new Cayman I realized the alignment was not right. I had the car back in and aligned -- the difference was night and day -- and my observations of tire temperatures was after having the car aligned.)

While this is a longer shot, be sure the tire is the identical to the other tire. Tread hardness, and so on. If the tires are unidirectional be sure the tires are mounted in the right direction. I would even go so far as to be sure the balance of the tire is ok, at least as good as the other rear tire. In fact, I'd even go so far as to be sure the wheels are identical, that somehow wheels with two different offsets didn't get fitted.

If you find nothing amiss which could explain the temp difference it could be normal arising from the road surface. If you are driving in such a way the tires on the left hand side of the car are running in say a shallow groove in the road surface caused by heavy traffic deforming the pavement this can have the wide rear tire experiencing side loads that can cause an increase in temperature. The narrower front tire may not be quite as affected by this road surface condition.

If you can drive the same road while placing the car in a different position in the lane or trying a different lane to see if the temperature differences are consistent.

If you want you can check temperatures after driving on different road surfaces. Try to find roads with less (or more) crown. If you find the temperature differences present but about the same from road to road this strongly suggests alignment provided of course the concerns about the tire differences and mounting I mentioned above have been checked.