The fourth-generation Audi A8 (D5, type 4N) represents the technological and status pinnacle of the Ingolstadt manufacturer. Launched at the end of 2017, it introduces a new styling language, a fully touch-sensitive interior interface (MMI Touch Response), and the generalization of 48V mild-hybridization (MHEV) across all its engines. A true technological showcase, it offers predictive active suspension, rear-wheel steering, and Matrix LED/OLED headlights. A facelift occurred at the end of 2021, modernizing the light signatures and the grille. Although its build quality is exceptional, its reliability is marred by recurring problems related to its 48V onboard network (alternator-starter), a major defect on the V6 engines of this generation within the VAG group.
The Audi A8 (D5) is an engineering prowess offering masterful ride comfort and silence. The gasoline engines (55 TFSI and 60 TFSI) are smooth and high-performing, perfectly suited to the car's standing. However, buying a used A8 requires extreme caution: the 48V mild-hybrid system (alternator-starter) is a true sword of Damocles whose failure is almost systematic and very expensive. Only buy an example with a crystal-clear history at an Audi dealership, with proof of the 48V BSG replacement, and ideally covered by an extended warranty. The significant depreciation makes it a tempting deal on paper, but maintenance costs remain those of a very high-luxury limousine.