ksalno

We have a 2011 A4 Sportline that my wife drives mostly. Prior to delivery, we had the dealer replace the summer performance tires with Conti Extreme Contacts in the same size 255/35 ZR19 96Y.

I was checking tire pressures today and according to the label on the B pillar these tires are supposed to be at 38 psi front and 42 rear, which sounds way high. I checked the manual and for the same size tire it lists 32 psi front and 30 rear. The max load numbers were also less than the B pillar. I know the B pillar label is for max load but that seems like a huge difference for 400 extra pounds in the back seat.

Which one should I go with? It's a pretty significant difference.

uberwgn

The B pillar shows only MAX LOAD conditions. Always refer to your Owner's Manual for detailed info on normal load.

Scotty (UK)

Audi recommend running at the Max Load pressures regardless of load.

Yep I know it's strange but they do on the B8. My sticker actually shows loaded and unloaded but there you go.

They say you should run the higher pressures unless you find it too firm and then you can back down to the unladen weight ... assumming of course you are unladen.

I've run mine (19's also) at the higher lever for the past two years and find it fine but then I do have the dynamic suspension so it may be different with the Sports or S-line suspension.

uberwgn

Scott, is this a published recommendation from Audi UK?

jadatis

You can re-calculate the pressure, with spreadsheet I made, in wich I use the same formula and system that the European tyre-makers used for decades, and since 2006 also the American.
https://skydrive.live.com/?cid=a526e...E092E6DC%21235
In this map on my public map of skydrive, click on the I in a cirlce at the end of the document you want, then in the right barr click download. After eventual viruscheck open it in Excell or compatible programm to use it. From this link you can navigate my complete public map like in a forum.
If you cant work it out, give me the details , and I will do it for you

Greatings from Holland
Peter

Scotty (UK)

On UK cars you get a DVD that you can load up in to the car. It's HTLM so I've pulled it onto my PC. In there, so I can cut n paste, it says :

_Tyre pressure and vehicle loading_

The tyre pressure must be adjusted according to the load the vehicle is carrying. We recommend adhering to the tyre pressure specifications for a maximum load. The tyre inflation pressures are listed on a sticker on the end face of the driver's door.

However, if you prefer an extra-smooth ride and the vehicle is not fully loaded, you can select the tyre pressure for a normal load (no more than three people travelling in the vehicle). However, should you wish to drive with a full load you must increase the tyre pressure to the specified maximum.

Under-inflation or over-inflation will reduce the life of the tyres considerably and also impair the car's handling. Correct inflation pressures are very important, especially at high speeds. The pressures should therefore be checked at least once a month and before starting a journey.

p.s. Scott is my surname

uberwgn

Ok, thanks for posting. It's completely counter-intuitive if one wished to maintain a uniform tire contact patch at each corner of the car. The MAX LOAD typically has the rear tires inflated 4 or 5 psi higher than the front even though the majority of the weight is carried at the front wheels.

Now, if you were operating a taxi service, then I could understand that recommendation....

Scotty (UK)

I don't get it either for the same reasons but mine seem to be wearing evenly so I'll stay with it.

uberwgn

I've been following the normal load theory on my car (+3 psi at each corner) and my tires are wearing nicely, too. Just rotated them last weekend.

SeaBlue

I was told the door sticker reflects the actual tire setup on the car. I just checked mine and it reflects the same tires I'm using and the recommended pressure is 33lbs front and 35lbs rear. I have the 18" Sport Pkg.