It's going up to 39 front and 44 rear. Feel like the ride is rough and I'm getting a lot of road noise.

I'm I starting too high? I'm following the manual. Maybe need be start cold at 32F and 37R?

Thanks for advice.

 

I believe the tire pressure recommended by Porsche is at a temperature of 60°F. Per tirerack (http://www.tirerack.com/tires/tirete....jsp?techid=73), you should adjust your pressure by 1 psi for each 10°F change in temperature.

For example, if you are inflating your tires, and you expect ambient temperature to reach 80°F, you should reduce your inflation pressure by 2 psi, from 34 psi Front and 40 psi Rear, to 32 psi Front and 38 psi Rear.

Don't quote me on this, but I believe the TPMS readout on your dash does automatically adjust for temperature. So if you inflate to 32 psi Front and 38 psi Rear at 80°F, the TMPS readout should show 34 psi and 40 psi respectively. (By the way, I find my TPMS to be pretty accurate, counter to experiences by others).

Finally, I also experience a lot of road noise (and steering wheel vibration) on my 997.1. I keep the tire pressures inflated per the owner's manual (33 psi Front and 39 psi Rear). When I drive the car, the pressures go up 2 - 4 psi, depending on the outside temperature. I have 19" Pirelli P-Zeros, and I just took my car to an indi because I thought there might be a mechanical, balancing, or alignment problem. The indi told me that the noise and vibration was due to the tires and that I should replace them.

So in addition to adjusting your inflation pressure for temperature, you should also check if your tires need to be replaced.

 

This is great information and I'll give it a try. As far as my tires...the car is brand new to me CPO car and as part of CPO new tires were put on. They are Continental Contact Sport 3's. They only have 600 miles on this at this point.

Part of me is wondering if I should sell the Conti's and get MPS2's...

 

You and I seem to be in the same boat with regards to road noise. You're considering a change in tires, and I have to get new tires.

I found some interesting perspectives here...

https://www.6speedonline.com/forums/...ntact-3-a.html

My indi recommended Michelin tires, but I want to do some research first.

 

Yep...I'm thinking about it..painful to have to sell brand new tires and have to spend more money on new ones.

 

Doh!

Yes, it does, well the TPMS readout that gives you the +/- PSI adjustment needed does adjust for temperature, in that it tells you how many PSI you need to go up or down to get to the proper tire inflation level for 'cold tires' (ie not warmed by driving, just sitting in the ambient air, at whatever temp that is)

 

u r fine with the tire pressure.

if the ride is too rough or u don't like the road noise, maybe you are in the wrong car. just kidding

seriously, tho, if u r running 19's and in a sportmode PASM, the ride around LA can be pretty tough. Best to set it on 'normal' suspension mode.

and as far as the tire noise, u can try different brand tires once ur current one needs replacement.. but it will still be noisier than most cars out there. There are even threads where people have added sound dampers such as dynamat to reduce the road/tire noise.

if u lower the air pressure, the ride will be 'softer' but the tire will wear faster and the performance will suffer.

BOL

 

Mine says 37F / 44R, "cold" inflation pressures. To me this means you inflate to that level while tires are not warmed up. At full warm-up my tires run about 39-40 F / 46-47 R.

 

I'm riding on Hankooks right now. Very quiet. For tire pressure...I'm running factory pressure but with Nitrogen. NO fluctuation in pressure at all. Stays the same hot or cold. Very little change if any I could see.

 

There is no need to adjust your tire pressure when the ambient temperatures rise or fall. If there were, your owner's manual would be full of Spring, Summer, Winter and Fall pressure differentials. Porsche, and all other manufacturers, know how much tires heat up when driving and their recommended pressures are good year-round. You can get more road noise as your tires age. You can certainly play around with your pressures depending on how and where you drive to determine the optimum pressure for you but don't need to adjust tire pressure for day-to-day driving.

 

If you are racing, specific tire pressures & temps matter a lot as you need the rubber to be most effective and last.

For driving, its not critical.. because the ambient air temp swings are less than the tire temp swings to maximum when driving. You just want to keep the tire pressure in the big fat 'working zone' for that tire.