ULEV has to do with
 

the application of emissins controls such as efficient fuel monitoring, max fuel burning, intake temps(quick warmup), advanced catalyst, and, yes, head design.

the 1.8T was a pretty dated engine even 10 years ago. and 5 head design goes back to at least early 80's Audi.

ULEV isn't particularly hard to achieve anymore, PZEV is the latest push.

Great now we'll get crap from both the B5S4 and B8S4 guys on how their forced induction cars are
 

superior to our normally aspirated RS4.

My S4 has been in the shop 6 times in 11 months for a total of well over 30 days...
 

and over 4 grand in repairs now. ANd I havent had one major failure yet. All 3 1.8t cars I had were bullet proof. I had $10 vaccum hose go once and a $20 boost hose go once. That's it. Long live the 1.8t :)

turbos get a bad rap from NA fans...
 

IMO, if you want high performance sports sedans/coupes, larger and larger v8's and now v10's are counterproductive. you lose the nimble and fast attribute and wind up with the car on steroids effect...everything gets bigger and heavier.

i don't know about "long live the 1.8T", as it's too small for anything but a Golf. but, turbo'd v6's in the 3.0 to 3.5 range sound wonderful to me.

I have no driveability issues on my 1992 S4 turbo.

Those 5 cylinders were bullit proof. 1997 and laters have lots of issues

LOL!

I put 66k miles on my 2000 S4 which was chipped right after break-in, 0 problems.

tell it to the other guy ^^^ : )
 

i'm a fan of turbos.

I like turbos too, I was just adding support to your argument that not everyone has had problems.