What causes a6 allroad rear suspension to sometimes drop but usually stays up. 

Probably the compressor as mentioned in:

https://www.audiownersclub.com/forums/topic/27161-rear-suspension/#comment-106137

https://www.audiownersclub.com/forums/topic/26506-front-suspension-strut/#comment-102910

 

Just got a nice set of 5 spoke alloys 8.5j x 19"

.what size tyres can be fitted to these for  an A6Allroad 2011. 

Thanks for looking 

Hello Renato,

The answer you need will be in the handbook for your A6 - as will the all important tyre pressures. 
Kind regards,

Gareth.

Thanks for the reply Gareth but the car didn't come with the handbook. 

Thanks Renato 

Well there we are then Renato. Now you need to search EBay to look for the handbook pack. Really shouldn’t be without it with such ma quality car. 

I'm on it. 

Thanks Renato 

Hi Gareth.. 

Just an update on the rear suspension issue.. Yesterday I took off both back wheels which is normal for me when I get a new car.. It's more to do with being sure and able to get them off in case of a puncture. 

While they were off I was squirting HRP foam spray looking for any possible leaks.. While in the area I also gave a good squirt to both of the rear levellers.. This morning, whilst in jacking mode, everything was nice and level and at correct height.. If the rear levellers were not functioning correctly, would that be a cause of the suspension dropping. 

If in jacking mode and no corners dropping does that indicate no leaks.. 

Thanks Renato 

Apologies Renato - back to wheels.

Some of the information you need maybe found on the label inside the fuel flap. 
Kind regards,

Gareth. 

Champion Gareth