ADias

Based on temp measurements and flex tests (chalk) to yield desired running pressures (typically 37/42) for proper handling.

This applies to a light load (up to 2 passengers and light luggage) and

Petza914

I run 35/40. Gues I could experiment with dropping these a couple psi and see what results are.

jadatis

First the TMPS can be set lower as the advice given on car, wich is pretty high.
Mostly 20 % below set pressure the alarm goes of, and sometimes also at 20% higher pressure.

Second as Chuck 911 wrote , there is no one ideal pressure , there is a range in the pressure in wich you can experiment.
But there is a lowest pressure for the weight on tires and speed you drive maximaly and wont go over for even a minute, at wich the tires wont damage by to high temperature at any part of the rubber, so it hardens and damages in next bendings so deflections of tire.

I myself set the maximum pressure calculated for when real load is 85% of weight the pressure is calculated for 160km/99m/h with the ideal formula to laws of nature.
Verry discussable and for low H/W tires this will be different, and could mean that damage and bumping can happen at same time.

I also made some lists about pressure chanche for temperature chanche and its depends on the cold filled pressure .
Better would be to go from a sertain % change for every 10 degr F.
I concluded cold advice to be for 65 degr F /18 degr C , but other say 68 degr F/ 20 degr F , but difference is that small that I dont worry about who's right.

syzygy333

thanks for all the info, esp. chuck911.
I feel like roller skates in a gravel pit.
will bring pressures down because bott's dots are loosening my fillings.

jhbrennan

Hard to believe that we are paying for air now - nice little profit generator for the dealers. BTW, I used Ni when I lived in Colorado and it seemed to hold pressures better even with the big temperature swings we experienced.

StormRune

Just for the sake of knowing Michelin's recommendations for the PSS's commonly found on our car (I assume in the 65 degree range as pointed out by others). The first number is the normal recommendation, the number in parentheses is the fully loaded recommendation. I've been running with the 33/37 crowd for some time but may try this out for a change. Odd that I stumbled on this on the UK page, I couldn't find the US page equivalent.

Raider89

OK, for novice rookie about to do first track day. Assuming I start with 35/40 cold temp, the pressures rise substantially when tires get hot as indicated on charts. So, after they get hot from first session and pressures have increased, should I keep checking and adjusting thru out the day? Is there an obvious hot tire target pressure for 2008 911 turbo based on your experiences for best track performance? BTW, I just bought new set of MPSC2 tires for track only.

ADias

On the track you need to bleed off pressure as your tires get hot. And.. starting at 35/40 for a 997 is too high, more like 32/36 or even less.

gopirates

I usually keep mine at around 31f and 33r and they warm up to around 34/36. I've run higher pressures before however this seems to be the sweet spot for my riding taste. Keep in mind I am running 18s and am not tracking.

ADias

You are running very low pressures and risk tire blowout or losing tire rim bead connection. Unless you drive sedately, always below 70MPH and low lateral Gs.

Astur

I'm somewhat hijacking this post because finding great sense in what Chuck says and as it applies to my DD 2009 997.2 C2 with 19" wheels, I set my pressures to 32/36. The problem is that even after the tires warm up to 32/36 I get a "Low Tire Pressure" warning that stays on all the time.

Hence I asked in another post (which nobody answered) if there's a way or setting to set say 32/36 as my default pressures rather than the Factory Setting for 19" wheels with summer tires?

ltcjmramos

The owners manual had the procedure for setting the baseline.

ADias

Setting 32/36 hot is too low and that is why the TPMS complains and rightly so.

Use 32/36 at 68F and all will be well.

I understand that the std sticker 36/44(PSI) cold is too high, as those are the tire pressures for a fully loaded car at German autobahn speeds and too high for American roads. Thus, 33/37 (or thereabouts) is the value long found for American roads and a normally loaded car (up to 2 people light luggage). 33/37 cold yields 37/42 hot on the road (out West for me) and it is fine.

If one is so affected by bumps and stiff suspension behavior to seek lower tire pressures too get a supple ride... either they have the wrong car or drive it on the wrong roads or both.

Astur

Although I respect your opinion but I must say that I find it to be a bit elitist.

I submit that not everyone who owns these cars is a Paul Newman or Steve McQueen wanabe who takes aloof pleasure in reminding their peers and other mortals what driving these thoroughbreds is all about while snickering at those who do not "heed the creed".

Mine is a DD which I enjoy immensely but I'm unwilling to accept the cost of shaking my fillings loose during normal city driving. True, I could have bought something that drives more "comfortable" but at this stage in my life (I'm retired) I not only wanted another 911 but was also unwilling to overly sacrifice my comfort.

ADias

Elitist?!? A 997 is not uncomfortable at all. At least not anything that lowering tire pressures to those low values will increase comfort but rather it will endanger tire life. If not an outright blowout, a breakdown of its steel belts. It's your car, do as you please, but think that not only you is at risk on the road. These are facts, not elitism.

Re shake and punishing ride... Make sure PASM Sport is not on and if you have Sport Chrono do do not run in Sport or Sport Plus modes on rough surfaces. Normal mode gives you the most compliant end of the suspension.