Just wondering really? Or are they just for petrol turbo's?

The latter. Plenty of stuff on why buried deep in this forum.

Yes you can run them

Absolutely no benefit

Probably lose bhp

So no benefit of running one a diesel then?

None, people who have them do it for the sound

I personally like the sound but think id get bored quickly and couldnt take the stick i'd get for having one lol

Buy a fake one lol loose no power but may loose friends :/

There is someone near me with an A4 tdi with one and it sounds as stupid as the body kit they have glued on it looks.

I had one on a stage 3 tdi golf with a hybrid vnt25

Sounded rather good especially teamed up with the decat milltek and massive hybrid tubby

Also wasnt all noise either