The Audi A4 B6 (internal code name Typ 8E) marks a major turning point for the brand with the rings. Replacing the B5, it introduced a design inspired by the A6 C5, a 45% increase in torsional rigidity, and an interior finish quality that set the standards for the category for the following decade. Although this report focuses on gasoline engines (highly sought after today to avoid traffic restrictions), the B6 also excelled with its diesels (notably the indestructible 1.9 TDI). It is a stately road car, available as a sedan, wagon (Avant), and convertible (produced until 2006). However, be aware: while manual and Tiptronic (Quattro) gearboxes are robust, the Multitronic continuously variable automatic transmission (front-wheel drive) is notoriously fragile.
The Audi A4 B6 is an excellent youngtimer, provided you choose the right configuration. For gasoline, the 1.8T 20V (150, 163 or 190 hp) paired with a manual gearbox (and ideally the Quattro system) is the best buy: powerful, reliable, and easy to maintain. You absolutely must avoid the 2.0 20V (130 hp) which consumes more oil than fuel, as well as the Multitronic automatic gearbox, a real financial black hole. The V6 gasoline engines are pleasant but expensive to maintain (timing belt). If you're looking for a diesel for long journeys, the 1.9 TDI (130 hp) remains a monument of endurance. Before purchasing, absolutely check the condition of the front axle and the absence of water ingress into the cabin.