History and Concept
Launched in 1991, the C4 generation was designed by Erwin Leo Himmel and marked Audi's definitive consolidation in the executive luxury segment, directly challenging established benchmarks in the European market. Unlike the C2 and C3 generations, Audi moved away from the fastback-style rear on the C4 Avant, adopting a traditional estate profile with an extended roofline and an upright tailgate. This transition significantly improved cargo usability, providing between 390 and 1,310 liters of usable space.
The C4 body structure made extensive use of high-strength, fully galvanized steel, delivering exceptional torsional rigidity and structural longevity. The vehicle came factory-equipped with the Procon-Ten (Programmed Contraction and Tension) passive safety system, which used steel cables anchored to the engine block to retract the steering column and pretension the seatbelts during a severe frontal impact. On models equipped with Quattro all-wheel drive, the rear suspension featured trapezoidal link arms that enhanced directional precision and ride quality.
V6 Engines and the High-Performance S4 Avant
The most significant technical evolution of the C4 generation was the introduction of Audi's first V6 engines: a 2.8-liter unit developing 174 hp and a 2.6-liter version producing 150 hp. The 2.8 V6 engine was notable for its variable-geometry dual-stage intake manifold, engineered to optimize low-end torque while ensuring responsive high-rpm power delivery.
In the high-performance tier, the brand presented the Audi S4 Avant (C4), powered either by a 2.2-liter 20-valve turbocharged inline-five engine (delivering 230 hp) or a 4.2-liter V8, paired with Quattro all-wheel drive and a five- or six-speed manual transmission.
Transition to the Audi A6 Avant Naming Scheme
Production of the Audi 100 Avant C4 concluded in late 1994. As part of Audi's global model nomenclature realignment, the C4 received visual and mechanical updates and was rebranded as the Audi A6 Avant starting from the 1995 model year, while the sporty S4 C4 was rechristened the S6 Avant.
C4 Avant Generation Powertrains
The C4 Avant brought together four-cylinder, five-cylinder, V6 gasoline engines, and advanced turbodiesel units.
| Engine |
Code |
Configuration |
Power |
Transmission / Drivetrain |
| 2.0 |
AAE |
Inline-4 8V |
101 hp |
5-speed Manual / FWD |
| 2.0 E |
AAD / ABK |
Inline-4 8V |
115 hp |
5-speed Manual or 4-speed Auto / FWD or Quattro |
| 2.0 16V |
ACE |
Inline-4 16V |
137 hp |
5-speed Manual or 4-speed Auto / FWD |
| 2.3 E |
AAR |
Inline-5 10V |
133 hp |
5-speed Manual or 4-speed Auto / FWD or Quattro |
| 2.6 V6 |
ABC |
V6 12V |
150 hp |
5-speed Manual or 4-speed Auto / FWD or Quattro |
| 2.8 V6 E |
AAH |
V6 12V |
174 hp |
5-speed Manual or 4-speed Auto / FWD or Quattro |
| 2.4 D |
MAS |
Inline-5 (Naturally Aspirated) |
82 hp |
5-speed Manual / FWD |
| 2.5 TDI |
AAT |
Inline-5 Turbodiesel |
115 hp |
5/6-speed Manual or 4-speed Auto / FWD |
| S4 Avant |
AAN |
Inline-5 20V Turbo |
230 hp |
5/6-speed Manual or 4-speed Auto / Quattro |