ADias

On 997.2s I think that a 4PSI difference is correct. On previous 911 gens 5 or 6 PSI diffs were typical. For 997.2s 33/37PSI was long established as a great all-around value, by well done tire thread temp measurements. For those who remember Gary Sims (may he RIP) he did that.

ALEV8

jadatis

Its not that tires have chanched but responcibilitys have chanched.
if one uses overweight or higher speed, and tires damage by that, nowadays the carmaker can be held responcible.
Your car has probably low hight/ width tires , and those to my conclusions as " pigheaded Dutch selfdeclared tirepressure-specialist" those tires are given to high maximum load or loadindex on sidewall, and for that reason need higher pressure then would be calculated with the official system.
the pressures higher back then front is what you would expect for a car with motor in back.
And I assume that your garage wanted to fill them even higher.
I am able to calculate a save pressure, but need tiredata and axleweights best weighed, and speed you wont go over for even a minute( so be hounest.

voiceprint1

I finally changed my pressure, the place that had mounted my 4S tires set them to 37/44 (as stated on the inside of the door), I set them to 34/40 as per the manual for 19 in rims partial load, and it made huge difference, every bit of the performance was better, turn in, braking, cornering, all improved. I had been feeling like the car was overly harsh on bumps and floaty, and setting that pressure took it right back to the feeling prior to the change. I was pretty amazed such a small change could make a difference, but it's much more planted and positive feeling.

Presto

mike cap

Lvt19672

32/36 is spot on.

fredke

Day after my 1st full set of Mich 4Ss I experienced my first Track DE day at Button Willow, CA 5/2018.
It took about 2 punchy 20 minute sessions until the tyres felt unsquirrely, and more settled. Those were at 34/41 F/R. It's a hot surface even in May. I swear the first few laps felt like I was driving with a skin of frozen snow glued on them.
Last weekend just replaced those same rears and left them at 36/44. Rears didn't feel so squirrely, but oh the mid tread fronts at higher pressure up to 144 mph felt like I was hovering the front end, never felt it like that before. And yes have had 4 wheel align recently. I think I am going to drop both about 2 and see how she handles.
Oh, and if you havent tried the 4S tyres, they are a ton more quiet than anything out there, and last about 2x s longer, as well as do better wet and colder.

tgil

Tire pressure critical even for street use -Owners Manual for my 997.2 coupe says 37/44 - think it was same for my 996 C4S and my 997.1 GT3.

My fat Michelins produce lots of road noise at highway speeds, but tried to adjust pressures down slightly to no affect, so I am back at 37/44.

Todd

tgil

Agree for track (MY first instructor a PCA racer with a 997 TT) insisted I run 30/35 cold temps.

Ironman88

I've settled on 36 / 42. Now that the ambient temperature has moderated here, those pressures seem to be working ok, at least for the driving that I am doing.

JustinCase

My tire/alignment guy has some sort of special computer program whereby he enters in my weight, the weight of my typical luggage (i.e., briefcase), and the percentage of time my wife rides with me. He also knows I am a street driver, albeit, I like my corners. The computer spits out the cold pressures, which are never 37/44. I have been getting 27,000+ miles per set (I always change the fronts at the same time) For my MPSSs, it was 35/41 cold, and for my MPS4s it has been 36/40 cold (C2S). I get mid-20s mpg on the highway, and perhaps 15 mpg around and about (lots of exciting curves here in the foothills).

Incidentally, my wife actually is a "grandma" (she prefers "Mom-Mom") who drives a 2016 Macan. Very aggressively, I might add. Historically, she was slightly better than me on the track the time or two we tried it. I have been practicing. Now I can beat her on the curves (i.e., with a slightly better line), but I have to really work at it. I can always catch her in the straights. But somehow, she has been pulled over more.