Tyre pressure question, what the owners manual quotes

[r1flyguy1]

Hi all,

Can you tell me what tyre pressures your running on your 997

I'm running 33f 39r on my 997tt which I read to be correct, yet I had a few hours to kil and came across the manual quoted figures of 34-40 for summer tyres.

Many thanks in anticipation.

r1

[MadMark911]

Everyone has a different view on this so you may get some differing opinions .....

Personally, I like my fronts about 1psi higher than they recommend and the rears about 2psi lower!

[r1flyguy1]

Cheers for the reply,

I guessed there may be a variety of views and opinions, I do recall reading 33/39 was the Porsche recommended pressures but then saw the below which confused me a little

Here's the page I am referring to,

[anonymous-user]

As it says 2.3/2.7 is what they recommend butmforma few years I have run mine on 2.1/2.5 as recommended by my indie, Paragon

Rides a little better, grips and handles just as well.

Tyres wear significantly more evenly.

[gsewell]

Not quite sure where your confusion comes. Two sets of figures. One for driver (possibly with passenger) and another for driver, one or more passengers and luggage.

It is just about the additional weight supported by the tyres. For day to day, use the lower set, and then if touring use the higher figures.

[r1flyguy1]

gsewell said:

Not quite sure where your confusion comes. Two sets of figures. One for driver (possibly with passenger) and another for driver, one or more passengers and luggage.

It is just about the additional weight supported by the tyres. For day to day, use the lower set, and then if touring use the higher figures.

Not quite sure you read my original post correctly

I clearly state, I had read official Porsche info on 33/39 tyre pressures, I also appreciate increasing PSI for extra weight, what I am asking is, has someone else also seen 33/39 as opposed to the book figures quoted or what their opinion is,

I cannot for the life of me find where I read the 33/39 figures but will update you when I find them again.

Cheers

r1

[anonymous-user]

There's no mystery here.

The Porsche recommended figures are 2.3 and 2.7 bar

This equates to 33.8 and 39.6 round down and you get your figures; up you get 34 and 40 ( which is a closer round up) I am sure you have seen 33 and 39 somewhere.

In my experience using those figures will give poor tyre wear, with the rears in particular wearing out in the centre before the outer areas.

[r1flyguy1]

REALIST123 said:

There's no mystery here.

In my experience using those figures will give poor tyre wear, with the rears in particular wearing out in the centre before the outer areas.

So what do you recommend ?

Cheers

[Gibbo205]

Hi there

I run 34 front and 37 rear. Drives superb!

[anonymous-user]

r1flyguy1 said:

REALIST123 said:

There's no mystery here.

In my experience using those figures will give poor tyre wear, with the rears in particular wearing out in the centre before the outer areas.

So what do you recommend ?

Cheers

As I said earlier I use 2.1/2.5 as recommended to me. Same as Gibbo on the rear, bit lower at the front.

Cold of course, they go up to about 2.3/2.8 or more once warmed up. (As seen on TPMS, which seems fairly accurate).

[jilap]

What I don't get is how rear 2 passengers and luggage can make any difference to tyre pressures. The back seats and boot space are so small that I doubt it would make much difference?

[Porkupine]

jilap said:

What I don't get is how rear 2 passengers and luggage can make any difference to tyre pressures. The back seats and boot space are so small that I doubt it would make much difference?

A couple of passengers and some luggage can add 200kg. That would certainly make a difference.

[anonymous-user]

Porkupine said:

jilap said:

What I don't get is how rear 2 passengers and luggage can make any difference to tyre pressures. The back seats and boot space are so small that I doubt it would make much difference?

A couple of passengers and some luggage can add 200kg. That would certainly make a difference.

I get your point but 200kg?

I doubt you could get more than maybe 25kg in the front boot and you'd never get two nearly 90kg people in the back. Not for long anyway!

[r1flyguy1]

OK

I have found the problem.

I downloaded the 997tt owners manual to my ipad and was reading through it using it as reference whilst I had a few hours spare...

I have just looked through both the quick guide and owners manual I have with the car and both state 33/39 for the tyre pressures,

So there is a stated difference between the downloaded manual and the one I have with the car.

Thanks all for your input.

[Helicopter123]

On the subject of Tyre pressures - how can I tell if my 997.2 has them fitted?

I suspect not but am looking for a set of spare wheels and this seems to be a factor.

[Mermaid]

Helicopter123 said:

On the subject of Tyre pressures - how can I tell if my 997.2 has them fitted?

I suspect not but am looking for a set of spare wheels and this seems to be a factor.

TPM? On dash

[tomw2000]

I had two new rears (Pzero rosso n1) on my 997.1 C2S the other day.

F*ck me. It's like a f*cking bouncy castle now. Nearly killed myself and everyone on the A1 this morning.

(Will check pressures at weekend and drive home steady this evening ).