My local dealer has a "new" Rx-8 with 2600 miles.

The tire pressure is 40psi all the way around.

How would 2600 miles @ 40 psi effect treadware/tire longevity?

Thanks!

 

Considering 44psi is the max tire pressure. (I believe) You crown the rubber and wear the center of the tire much fast with overinflation.

 

so this is probably a dumb question...but what psi do you have your tires at???

 

I have mine between 32-34 psi. But I have 18x8.5 wheels. So slightly wider than stock. My tire is also 245-40-18.

 

I've been running 34 PSI in mine and they are wearing nicely. I have stock wheels and tires (225/45/18) I doubt that 40 has hurt anything in 2600 miles. You can do the coin trick to check tread depth across the tires. Roll a coin in the tread groove until a mark on the coin matches the depth, then go across the tire grooves, from inside to outside and see if the same spot matches each groove. You should be looking for more or less depth in the middle grooves, compared to the edges.

 

You are right. The service department measured the tred and it had worn evenly.

Despite the fairly aggressive discount below invoice due to the miles, I passed on the car and bought another one that was fresh.

Figured it was worth the extra money for the piece of mind to know that I was the only driver and that the car was not abused by some nit wit.

 

Amen, brother.

 

Don't set at the manufacturer standard...

The porsche indicate their car to put on 42psi and I doubt their tyre are any different grade (they are still W rated for speed)

I put 39psi all round but will go to 40-42psi on the track.

I have 40psi all round for my sedan whcih mainly do highway miles. There is more even grip with 40psi than 32psi as a flat tyre surface on the road...

On a highway, your tire heat up and go to 44psi anyway --- by reducing the gap you reduce the flex on the side wall and reducing heat perhaps...

Time and time again the defense driving course teach people to have any car to go 36 psi all around and sport car to 40 when on the track... mine instructor said 42 before going to a race track last time.