The fourth-generation Audi A8 (D5, type 4N) represents the technological pinnacle of the brand with the four rings. Launched at the end of 2017, it massively introduces mild hybridization (MHEV 48V) across all its engines and an ultra-sophisticated predictive active suspension. Initially designed for level 3 autonomous driving (ultimately abandoned for legal reasons), it is packed with ECUs and sensors. Facelifted at the end of 2021 (2022 model) with new OLED optics and a redesigned grille, it shines with its imperial comfort and soundproofing. Overall reliability rating: Mechanically very robust (especially the V6 TDI blocks), its rating is however burdened by extreme electronic complexity, infotainment bugs, and a recurring fragility of the 48V alternator-starter system (BSG).
The Audi A8 D5 is an impressive technological showcase, particularly relevant in the 50 TDI engine for very high mileage drivers thanks to its range and cathedral-like silence. However, this generation is marred by a chronic fragility of its 48V network (alternator-starter), a costly and immobilizing problem. Buying a used A8 requires a crystal-clear maintenance history, strict verification of performed recalls (especially on the running gear and electronics), and ideally, an extended warranty. Avoid urban models (TDI clogging) and negotiate firmly given the steep depreciation.
| Oil change | £140 – 250 |
| Timing chain | £2 200 – 4 500 (remplacement rare, non préventif) |
| Complete brakes | £650 – 1 200 |
| Estimated annual budget | £850 – 1 700 |
Indicative estimates (independent garage, UK market). Prices vary by region and year.