18" Wheel Tyre Pressure Help Needed

[wheely88]

I keep getting different responses on the correct tyre pressure for my 2 wheel drive A4 Avant 2.0TDI. Even local audi dealers are struggling.

Car came with 17" wheels so door sticker doesnt give 18" recommended pressures. Searched on here at varies between 36 and 42 (Audi told me 34F, 32R) but nothing points exclusively to my model.

So can someone with a similar car, with factory fitted 235x40x18" wheels/tyres on a similar model please let me know what the recommended pressure is (for both unladen and laden).

Right now I'm running 36 front and back.

Thanks in advance

Mark

[OVI82]

I used to have a pair of 18" alloys on my car and used to put 36 psi in them at all times.2 years later I find out my alloys are bent and it could be because I had to much air pressure in there.(that's what the guy at my local tyre shop said).I replaced them with 17" now and I've got 30 psi in them.my previous alloys where replicas so not very well built.I personally think 36 is more than enough.plus the more psi you got in there the harder the ride will be.

[mikeybutch]

We have these on a B6 and the factory sticker says 41 all round unladen.Genuine alloys will not be affected by higher pressures which low profile tyres need.The 205/55/16s on myB6 Quattro had 38 all round

[GarJE]

Got mine on 42 all the way around. Tread wear is perfect (6-6-6) on each tyre last service.

[Lateknight]

Mine states 35psi for light laden. 39psi for heavily laden. (pressures are for cold tyres). I always check mine to 36psi (2.5bar)
Oddly enough the sticker also contains 17" and 16" wheel pressures

[thomas_lad]

Mine are always at 32psi

[jdp1962]

The recommended pressures are a guide, and are intended to provide a compromise between handling, ride comfort, steering response, noise levels and fuel economy. They are not an absolute from which you must never vary. Within limits, you can experiment with a range of pressure until you find the one that suits you best. I'd avoid going below 32psi or higher than 42psi. Mine are 17s, and I run them at 38 all round.

To the OP, if you are finding 36psi works for you, there's no need to change. But like I said, play around with different pressures, and you might find one that suits you more.

[ming]

Technically, the tyre pressure for a particular car remains constant irrespective of tyre/wheel diameter.
If you want corroboration, just give one of the manufacturers a call.

[jangles]

Adding to the answers here, I have 18" rims with 235x40x18 tyres as standard on my A4 TDI S-Line. Here's a photo of the tyre pressures sticker on the drivers' side door pillar that shows pressures for various tyre sizes:

http://farm6.static.flickr.com/5211/5517379791_1172bc72ca.jpg

At the bottom, you can see that the recommended pressure for 235x40x18 tyres is 35 PSI for normal load, 39 for fully laden. I tend to have my tyres at 36 PSI. Much depends on the type of tyre, though, whether you have XL (reinforced) tyres or not.

Hope this helps.