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Tyre Pressures

sTTu

Well-known member
Joined
29 Sep 2006
Messages
320
Been trying different tyre pressures today. Looking at the plate on the drivers door frame, its says fronts 34psi & rears 40psi but when putting it round a few twists it felt decidedly sloppy after the higher pressures that I had it at (and were the pressures that the OPC had it at when I got it) It was running at 37psi front and 47psi rears, I thought this was a bit high but maybe not??Any recommendations ? Thanks

Migration info. Legacy thread was 131199
 
are those checked at cold or when running warmed up ?

OEM is cold temps so tyres will heat up by 10-20% over the cold and depending on your driving




Migration info. Legacy thread was 131222
 
Those were cold pressures, the original pressures just seemed high but I guess those back tyres are quite big. The handling was very different with the pressures lower.

Migration info. Legacy thread was 131229
 
I am interested in the tyre pressure issue and was hoping someone could shed some light.

Migration info. Legacy thread was 131555
 
34f/40r COLD are the correct pressures (±1psi). Anything higher and your tyres will be seriously overinflated when hot causing balooning through the middle.

Most (if not all) high performance tyres (including N-rated) recommend a MAX pressure of 50psi. If you are start at 47 cold on the rear, you will exceed the tyres recommended operating pressures.


Migration info. Legacy thread was 131560
 
I use these pressures on my door plate - yours will be different if its not a 993.

Porsche put them there so I know how to pump up my tyres to the pressures which will give the best grip, puncture resistance and mileage - as well as safety up to the maximum speed of the car as determined by Porsche development engineers using years of experience and thousands of miles of testing.

Cold tyres - means tyres which have not been driven for two hours and means at the ambient temperature - that's right ambient - winter or summer - Finland or Nice in the south of France use the settings on the door plate (also in the MANUAL - with lots of safety advice).

You don't have to accept what I - or Porsche say - its up to you as the owner.

Here are a few words from a friend of mine who

Drives for Ferarri
Drives for Porsche
Drives for Aston Martin
Drives for Maseratti

Amongst other high performance marques.

He regularly drives new owners and dealer staff on racetracks to show them the full capabilities of the latest cars.

I asked him - "what do you do about tyre pressures."

He said - "I use the manufacturers stated pressures as the manual says - why would I do otherwise?"

/images/migration/UploadedForumImages/CIMG2092sss.jpg

Migration info. Legacy thread was 131587
 
I've tried lot of different pressures with different effects on my 997S

As a guide line just follow the recommendations on the door panel.

When traveling high speed on motorways I put 44psi Rear/37psi front. This gives harder ride with good fuel efficiency.

I was on Nurburgring this weekend I stayed on this pressure (temp 13c) and I was sliding all over the place, so like previous times I reduced it to 40/34 and the grip was far better.

In the wet or cold I make sure that I bring pressures down to 39/33 to get even better grip.

I always check pressure when car's been standing still or in petrol station which is less than a mile away and I avoid braking and hard acceleration in that mile. You'll be surprised even in winter the pressure can rise by 2-4 psi even after few miles of driving.

I had the same problem when car was delivered the pressures were just way too high. My explanation was I got my car in January and they must have pumped the tyres in very cold temperature and when I got the car it was quite warm for january.


Migration info. Legacy thread was 132225
 

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