The b8 version came with a 4.2L N/A V8. Unlike the b8.5, which was a 3.0 turbocharged v6, the naturally aspirated V8 offered little room for power upgrades on the factory motor. Most stock S5 b8’s dyno at 280-290whp / 280 wtq.

As for the bolt-on mods on the N/A, you’re limited to an exhaust system, intakes, and a tune…that’s about it! Depending on which performance parts/company you go with, the most you would get would be around 340whp/330wtq. Beyond that, you would need to drop in a supercharged to get anywhere near the 500 wheel.

Since I was happy with my APR RSC Exhaust, I decided to stick with APR and get
– ECU upgrade adding +15 HP / +14 Ft Lbs torque.
– Carbon Fiber Intake System with a claimed +10 HP.
– RSC Exhaust System (IMHO, the best sounding exhaust on a B8 S5!) My Review here