DeutschDriver

are they battery powered? if so, how often do they need to be changed?

also, does the spare function the same?

Plano-4.2

YMMV. Audi will not replace them until they fail. I've had 3 of the 5 replaced.

DeutschDriver

and idea of non-warranty replacement cost?

geordie

The unit is sealed so the battery cannot be replaced. I seem to recall that you can see battery life remaining using VAG.com
Audi will charge around US$150 per sensor plus you may need valve stems. I forget the price of these.
I believe you can get the identiacl sensor from Tire Rack for under $100 each
The spare is identical.
The A8 has 5 receivers to sense each wheel. Other models use a less sophisticated setup.

greenie

Ditto to the availability from Tire Rack.

snowpilot

i've got a aftermarket set of rims and tires and was wondering if it was worth it to buy an extra 4 tire pressure sensors? I'm going back and forth because i'd have to have these unmounted and have the sensors put in and then remounted.

plus there aren't many places where i live that i would trust to put a pressure sensor in.

thoughts?

MEGATAYLOR

The TPMS is manufactured by a company called beru. You can download all the fitting and setting instructions from www.beru.com

greenie

Id go with new sensors for the other wheels.