Re: Pre and post turbo injection in an audi b5 s4
 

How much miles/Pulls did the plug's have seen?
I also agree, that this is a lot of soot for 13.5:1 AFR.

Mine look much cleaner on the top of the thread plateau even with 12:1 without WI activated.

Re: Pre and post turbo injection in an audi b5 s4
 

Maybe 200km with mainly high revs.

My engine is 8.5:1 compression with stock head and GT2560R turbo.