DollarB22

Just got my 04' Black S4 last week. Had it tinted this weekend and now I am looking into some basic "mods" (Rims, Exhaust). I did a search but my questions are so basic that it's hard to search. What is the favorite exhaust of the board members. Can I expect a significant performance increase?? MPG increase?? Are they obnoxiously loud like the "boy racers" or just throaty and deep sounding?? Thanks in advance for any help...

RS4abob

"Favorite" is a personal preference, but many on this board have Miltek. It is available either cat-back only (which eliminates any potential warranty issues) or the full system with hi-flow cats & downpipes. Cat-back (available resonated or non-resonated) is a pretty quick easy DIY install. Downpipes a bigger PIA and more time consuming.

I have the resonated cat-back & it sounds exactly as you describe - just deeper and throatier than stock - not at all "boy racer". Power gains are well documented, but not significant enough to be obviously felt in the butt dyno. As to gas mileage, probably a touch better in a highway mode, because it is definitely less restrictive. Problem around town is that it sounds so good, you will want to listen to it more, and guess what - that uses gas :-)

Also would definitely recommend both the hyperflow intake and short shifter kit from Stratmosphere - both are great improvements

S4SpdWgn

I went with Milltek DP's and resonated Cat-back. I compared my car before and after the install with other S4's and I would say it's the biggest HP increase and performance mod you can buy for the B6 S4. The performance increase for straight line running and lap times at the track are significantly faster, especially beyond 5,000 rpm's.

The other benefit is the sound...OMG! Many will tell you the sound is almost worth the $$.

LoveV8

is this John