Audi A6 C8 (4K) (2018 – 2025)

Reliability score : 7.8/10

The eighth-generation Audi A6 (internal code C8 / 4K) marks a major technological turning point for Ingolstadt's executive sedan. Launched in 2018 and facelifted in 2023, it stands out with its ultra-modern cabin featuring a dual-touchscreen (MMI Touch Response) and the widespread integration of mild-hybrid (MHEV) technology across almost all its powertrains. Based on the MLB Evo platform, it offers imperial comfort, top-notch sound insulation, and impeccable finish quality. While gasoline engines (TFSI) have gained reliability compared to previous generations (notably the mature 2.0 EA888 unit), this C8 generation is marred by a recurring and costly problem related to its 48V mild-hybrid system (starter-generator) on V6 engines. It is an excellent road car, but its electronic complexity r

⚠️ Weaknesses

Disastrous reliability of the 48V starter-generator (BSG) on V6 engines
Questionable ergonomics of the all-touch interface while driving (climate control)
S tronic gearbox sometimes hesitant on takeoff or at low speeds
Very high maintenance and spare parts costs
Significant weight, especially on PHEV (TFSI e) versions

🎯 Verdict

The Audi A6 C8 is an impressive technological showcase and an exceptional road car. If you are looking for a gasoline engine, the 2.0 TFSI (45 TFSI) is the most rational and reliable choice: the EA888 unit has now shed its old demons and offers an excellent compromise. However, purchasing a V6 version (55 TFSI or TDI) requires great caution: the 48V starter-generator (BSG) problem is a real financial sword of Damocles if the vehicle is no longer under warranty or if the part has not been replaced by the revised version. Prioritize a model with a clear service history within the Audi network, and do not hesitate to subscribe to an extended warranty for V6 or PHEV models.

Common issues

Problèmes du système MMI Touch Response (bugs logiciels, écran figé) Medium

🔧 Dès l'acquisition, variable

💶 0 € (mise à jour logicielle) – 1 500 € (remplacement module)

Vérifier les mises à jour logicielles et le fonctionnement de l'écran tactile.

Défaillance du système Mild-Hybrid 48V (batterie ou alterno-démarreur) High

🔧 50 000 – 120 000 km

💶 1 500 – 4 500 €

S'assurer que le système 48V a été vérifié lors des entretiens réguliers.

Fuites de la pompe à eau ou du boîtier de thermostat Medium

🔧 80 000 – 150 000 km

💶 600 – 1 200 €

Surveiller le niveau de liquide de refroidissement et les traces de fuite.

Consommation d'huile moteur (pour certains moteurs TFSI) Low

🔧 Dès 60 000 km

💶 Coût de l'huile (faible) – 4 000 € (si réparation moteur)

Vérifier régulièrement le niveau d'huile et faire l'appoint si nécessaire.

Estimated maintenance costs

Oil change	£130 – 250
Timing chain	£1,600 – 3,000 (if needed)
Complete brakes	£400 – 750
Estimated annual budget	£650 – 1,300

Indicative estimates (independent garage, UK market). Prices vary by region and year.