Best Spark plug for Audi A4

Denso iridium are great for turbo cars

NGK are also good, but in experience denso iridium works better when running more than 1 bar of presseure

Bosch F5DP0R on a T3/T4 50 trim at 25psi daily. Love it.

I went to the dyno today and ended up with some pretty good #'s 321HP 304TQ Car was ran on SPS3 settings boost 9 timing 9 with Sunoco gt100 fuel. Temperature was mid 70's My car: 2003 A4 1.8t quattro ATP/Revo GTRS ATP Manifold Ecode Front Mount Intercooler Ecode Test Pipe Neuspeed Xtreme Turbo intake pipe Neuspeed Exhaust Stock airbox with K&N panel filter stock N75 valve working And NGK BKR7E plugs South Bend OFE SS clutch I could have done better if I had the right plugs (Bosch 3 electrode) and a manual boost controller but im pretty happy overall. Also the car was pulling 0 correction factors all the way through the rpm range so Lemmiwinks could have helped me with some more timing.

I just installed some of these NGK (BKR6E) plugs. I set the gap to .030 These went my 99 A4 1.8T Avant Quattro. The car is stock except for a K&N filter. Idle seems awesome and flawless all the way through the rev range.

I use Beru Utra-X UXF79 4 tips plugs. It's a great plug for my chipped B6.