I have 190,000 miles on a 1998 Audi A4 Turbo Quarttro and engine is still running strong. Have done regular maintenance and oil changes every 3k-4k miles with Moble1 0W-40W Synthetic.
The 1.8 turbo is more powerfull. The turbo charger pushes more air and fuel into the engine.
The 2008 Audi A6 has a V6 engine.
The 2008 Audi S4 has a V8 engine.
The 2008 Audi Q7 has a V6 engine.
The 2008 Audi R8 has a V8 engine.
The 2008 Audi A5 has a V6 engine.
The 2008 Audi A8 has a V8 engine.
The 2008 Audi S5 has a V8 engine.
The 2008 Audi S8 has a V10 engine.
The 2008 Audi S6 has a V10 engine.
The 2008 Audi TT has an inline 4 engine.