The 1990 Audi 100, part of the C3 generation, represents a significant era in German automotive engineering, renowned for its sophisticated design and robust construction. As an executive sedan and wagon, it competed with established luxury brands, offering a comfortable ride, advanced features for its time, and a distinct aerodynamic "tear drop" design. A key differentiator was the availability of the groundbreaking quattro all-wheel-drive system, underscoring Audi's commitment to performance and all-weather capability. This model exemplifies German engineering quality, focusing on durability and a refined driving experience for discerning owners. This comprehensive Factory Service Manual (FSM) is your authoritative guide to the service and repair of the 1990 Audi 100. With over 1500 pages of detailed information, it covers all major systems, including engine variants, manual and automatic transmissions, front-wheel and quattro drivetrains, suspension, brakes, steering, electrical systems, and climate control. The manual provides essential procedures for scheduled maintenance, diagnostics, component repair, and major component rebuilds, along with critical technical specifications like torque values and fluid capacities. It is an indispensable resource for owners, mechanics, and technicians aiming to maintain the optimal performance and longevity of their Audi 100.