997 Tyres pressures...optimum road settings?

[turboman786]

997 C2 (3.6l)

What pressures are best for road use, with no passengers?

Im running 37psi all round at the momnt, but was wondering if there is any particularly recomended set up....

[porscheuro]

it should state on your "b" post what is required for your vehicle, black sticker i think it is and not 100% sure but its around 34psi on front and 40psi on rear..

[DSM2]

For what it's worth:

The book says 2.3 bar and 2.7 bar cold for my 997S. (34psi / 40psi)

I noticed when it was first serviced a year ago by Tonbridge OPC they returned it with 2.1/2.5.

When Paragon gave it a once over and oil change for me the other month, they returned it with 2.1/2.5.

The first set of tyres was changed immediately prior to its first service and the rears had definitely worn more in the central part of the tread, normally an indication of over inflation.

So my experience seems to indicate that 2.3/2.7 is too high and the OPC and Paragon seem to prefer the lower pressures. 2.1 = 31psi; 2.5bar = 37psi.

I can't feel any difference in ride or handling, in road use.

I know I should have asked the OPC and Paragon why they use those pressures, I keep meaning to but haven't yet!

[Country Boy]

Mine isn't a 997 but a 996 and the Indie recommends very low pressures of 28psi and 32psi. I ignored him at first until the last annual service when he confirmed rear tyres worn out after around 3000 miles!! Overinflated as worn in the centre. I now run tyres on his recommended pressures and the ride is by far superior and I'm keeping an eye on wear to see if the new tyres wear on the outside. I don't think they will!

[arcamalpha]

997 GT3 says 29/31 at 20degrees which has given me even wear so far (tyres are 235/35R19 and 305/30R19).

I was very surprised to see such high pressure for non-GT 997s, but I guess the tyres sizes could be quite different, and obviously a touch more weight. What are the tyres sizes on your Carrera?

I tend to run pressures a touch low anyway and they're chosen at least partly to enable the car to run up to full speed, which I never get near!

[DSM2]

arcamalpha said:

997 GT3 says 29/31 at 20degrees which has given me even wear so far (tyres are 235/35R19 and 305/30R19).

I was very surprised to see such high pressure for non-GT 997s, but I guess the tyres sizes could be quite different, and obviously a touch more weight. What are the tyres sizes on your Carrera?

I tend to run pressures a touch low anyway and they're chosen at least partly to enable the car to run up to full speed, which I never get near!

Really? Are you sure it isn't 2.9 and 3.1 Bar?

My 997S has those same tyre sizes and the recommendation is 34/40psi. I would have thought the more powerful, faster and sportier car would run higher pressures but as I said earlier, there seems to be a lot of difference of opinion of the best pressures to use.

[Ian_UK1]

I always ran my previous 997S at 34F/40R. Tyre wear was always completely even across the rear tyres. The fronts used to wear the inner edges by 1mm more than the outer by the end of the tyre's life but this could be due to slightly more aggressive cambers than standard. I'm using the same pressures on my new 997S but I haven't worn-out its first set of tyres yet (I am working on it though ) Tyre wear so far is in line with my previous car.

When I did some experimentation with tyre pressures, I always found going below 40psi on the rear made the car move around too much (not in a positive way - more in a 'what's it going to do next' way). Going to 44psi for an extended period of time led to the middle of the tyres wearing more than the edges. Going to 35/36 up front can give a little more bite into corners but I found this to be dependent on the tyre make. Pirellis responded well, Made no discernable difference with PS2s. Turned out sticker pressures gave the best all-round result in the end.

Don't forget you need to set your tyre pressures cold. At working temp the measured pressures will be several psi higher than sticker. If you set the pressures to sticker when hot, they'll drop away far too far when cold.

[arcamalpha]

DSM2 said:

arcamalpha said:

997 GT3 says 29/31 at 20degrees which has given me even wear so far (tyres are 235/35R19 and 305/30R19).

I was very surprised to see such high pressure for non-GT 997s, but I guess the tyres sizes could be quite different, and obviously a touch more weight. What are the tyres sizes on your Carrera?

I tend to run pressures a touch low anyway and they're chosen at least partly to enable the car to run up to full speed, which I never get near!

Really? Are you sure it isn't 2.9 and 3.1 Bar?

My 997S has those same tyre sizes and the recommendation is 34/40psi. I would have thought the more powerful, faster and sportier car would run higher pressures but as I said earlier, there seems to be a lot of difference of opinion of the best pressures to use.

Yup, but I'm going to double check when I get home now!

Temps once the tyres have warmed up after 20 miles or so tend to be 31/33 for normal driving or 33/36 for something a bit more spirited.

[gubbs997]

I have always used 34/40 Psi and sometimes higher at the rear if loaded up. I do notice if the fronts drop below 34 as gets heavy, and as for tyre wear that seens to be much more driven by alignment with the camber that modern porsches run the insides always wear out first.