(Another thread about) tyre pressures!

[Scott]

Hi All,

I went back to the garage which fitted my coilovers & ARB's today and had them check the tracking, which was very, very slightly off and has been corrected. I'm currently lowered on Weitec coilovers with Eibach ARB's and IMO the handling is good but lacks feel.

Without a full geometry setup which I can't afford at the mo, or 4 new tyres which would probably help, I guess it's all down to the tyre pressures now. Audi recommends 42psi front and 36psi rear for 225/40R18's and I don't like that. I've been running anywhere from between 37-39psi front and 33-34psi rear and I think it feels much better. However I have been told to try 34psi front and 36psi rear. I have a few questions.

1. would this be a good idea or is there an obvious reason why dropping to 34psi front or having a higher rear pressure than front would be bad?

2. how would this affect tyre wear if I'm driving like I normally do but with lower pressure?

3. what tyre pressures do you guys all use/recommend, fwiw I have a 2.0 TDI.

4. anything I've missed?

Many thanks
Scott

 

[Staz]

Running lower pressures increases rolling resistance and increases fuel consumption. It also increases grip down to a point. Higher pressures do the opposite.

The recommended pressures are higher up front because they have to cope with the weight of the engine whilst the rear has just the car body.

I am also running 38F-34R and it's been great up to now and wouldn't try swapping the pressures. You can always give it a try but I'd take it a little easy at first before trying out the limits.

 

[pdv40]

Umm where did you get 42F 36R from?

I've got a 2.0 TDi Sportback on the same size tyres as you and my recommended tyre pressures are 38 all round for max load at 100KM/H + and I currently run at 35F 30R as per the filler cap.

 

[Purple Princess]

On the 18's I run 36f 38r, gives a nice compromise between feel and resistance on my A3 TQS

 

[Scott]

Umm where did you get 42F 36R from?

I've got a 2.0 TDi Sportback on the same size tyres as you and my recommended tyre pressures are 38 all round for max load at 100KM/H + and I currently run at 35F 30R as per the filler cap.

Well that's what it says on my door for 225/40R18 - 42f 36r for 'minimum load' - of course, I'll double check this tonight when I get home...

I think I'll give 34f, 36r a try tomorrow.

Thanks all...

 

[Scott]

100% sure for my tyres w/ a low/medium load, the tyre pressures (as given by Audi) should be 42f 36r. How strange....

 

[paddy]

I have 225/40R18's and use 40psi all round...works for me

 

[VWAddict]

I've noticed centre-line wear is a little heavy using the factory recommended pressures, so I've lowered mine to 34F / 30R.

If you're using higher rear pressures, make sure that you keep a good depth of tread on the back tyres, or you might find the back end a little willing to 'snap-away' suddenly in the wet... -Just a thought.

Keith