a6 avant undertray

[mr brightside]

what an exciting thread title!

anyway, are these really necessary? Mine is ripped to pieces where the missus keeps parking it over the kerb so often gets stuck, so it looks a right state.
I also think it flaps about a bit as it makes a racket going over potholes etc.
Presumably it is there to protect the belt as that looks a bit low, but can i not just take it off and chuck it in the bin?

[blueg33]

I am on my third undertray under warranty! Protects bottom of the engine, surely there must be a reason for it

[T89 Preparation.]

On most cars I have found them fairly useless but on Audis there is a good reason to have one.... on my Audi 80 1.9tdi (and many other Audis) the power steering pump and belt are right at the bottom at the front, if you drive through a puddle the belt gets splashed and you lose power steering (which means you lose virtually all steering) this is vary scary and very dangerous.

[Raven Flyer]

The main reason for these trays is to make the car more aerodynamic underneath. This is a win-win with better mpg due to less drag. You also protect the lower mounted components from water but this is a lesser concern or the trays would be small and just protect the vulnerable kit.

[TonyHetherington]

Raven Flyer said:

The main reason for these trays is to make the car more aerodynamic underneath. This is a win-win with better mpg due to less drag. You also protect the lower mounted components from water but this is a lesser concern or the trays would be small and just protect the vulnerable kit.

Indeed. When even the lower engined cars are capable of 130+ mph, at those sorts of speeds air flow control is crucial - and a nice flat floor under the engine sends the air underneath your car ncie and smoothly, rather than getting caught in the pockets caused by strange shaped things in the engine bay.