Audi S4 B6
2004-2005
The B6 S4 represented Audi's answer to BMW's M3, offering V8 smoothness over turbo complexity. Its naturally aspirated engine delivered linear power delivery with a more traditional sports sedan character than its turbocharged predecessors.
Quick Take
The B6 S4 marked Audi's transition from the beloved twin-turbo V6 to a naturally aspirated V8 for the S4 line. This generation featured quattro all-wheel drive and a choice between 6-speed manual or CVT transmission. It represented Audi's premium sport sedan offering during the mid-2000s.
Best For
Key Strength
Tuning Goldmine
Watch For
Engine Reliability Concerns
The Story
Heritage & Legacy
Part of Audi's S4 lineage that began in the 1990s, the B6 generation moved away from the twin-turbo setup of the B5. This marked a philosophical shift toward naturally aspirated engines that would define Audi's performance cars of the mid-2000s.
Design Philosophy
Audi prioritized refinement and reliability with the B6's naturally aspirated approach. The design emphasized understated aggression with subtle aerodynamic enhancements and the classic Audi interior luxury expected from the four rings.
The Driving Experience
Engine Character
The 4.2L V8 provides smooth, linear power delivery with a refined soundtrack that builds to a crescendo at higher RPMs. Unlike the explosive turbo character of its predecessor, this engine rewards smooth inputs and high-rev driving with cultured V8 refinement.
Chassis Dynamics
The B6 S4 offers composed handling with quattro all-wheel drive providing excellent traction and stability. The suspension strikes a balance between sport and comfort, though some enthusiasts found it less engaging than the more tail-happy rear-drive competition.
Sound Signature
Classic German V8 growl with a sophisticated exhaust note that's more refined than aggressive.
Strengths & Tradeoffs
Defining Strengths
The 4.2L twin-turbo V6 responds incredibly well to modifications, with simple tunes adding 100+ horsepower. The platform has become legendary in the tuning community for its potential to reach 500+ horsepower with supporting modifications.
Audi's legendary all-wheel drive system provides exceptional traction in all conditions. The 40/60 torque split and torsen center differential create predictable handling characteristics that inspire confidence on both street and track.
Honest Tradeoffs
The FSI engine suffers from carbon buildup on intake valves requiring expensive walnut blasting every 40-60k miles. Timing chain guides can fail around 100k miles, leading to catastrophic engine damage if not addressed proactively.
German luxury car ownership means expensive parts and labor. Even routine maintenance like oil changes and brake service cost significantly more than mainstream alternatives, and major repairs can easily exceed the car's value.
Ideal Owner
Perfect for enthusiasts who want daily usability with performance credentials and appreciate naturally aspirated engine character over turbo drama.