Mercedes GLS X167 (2019 – 2025)

Reliability score : 7.4/10

The Mercedes-Benz GLS (Generation X167) is the flagship SUV of the brand with the star, often described as the "S-Class of SUVs". Launched in 2019 and facelifted in 2023, it offers up to 7 seats in absolute luxury. Based on the MHA (Modular High Architecture) platform, it stands out with its impressive technological arsenal, including the MBUX multimedia system, 48V mild-hybridization (EQ Boost) generalized on gasoline engines, and the optional E-Active Body Control suspension. Although its road performance and comfort are exceptional, its reliability is sometimes marred by the complexity of its onboard electronics and its 48V network.

✅ Strengths

Imperial ride comfort (especially with E-Active Body Control)
Gigantic space on board, including in the 3rd row
Very high-level soundproofing
Extremely high-performing and smooth L6 (M256) and V8 (M176/M177) gasoline engines
Onboard technology and quality of MBUX displays

⚠️ Weaknesses

Capricious reliability of the 48V mild-hybrid system (ISG) in the early years (2019-2021)
Oversized dimensions (5.20 m) unsuited for European city centers
Astronomical running and maintenance costs (21 to 23-inch tires, brakes, insurance)
Very high weight (over 2.5 tons) causing premature wear on the running gear
Various electronic bugs (screens, driving assistance sensors)

🎯 Verdict

The Mercedes GLS (X167) is a pinnacle of luxury and space, but it pays the price for its technological sophistication. The gasoline engines (GLS 450 and V8) offer exceptional drivability, but the 48V mild-hybrid system (EQ Boost) had a difficult start (starter-generator failures), particularly on 2019-2021 models. If you opt for a gasoline model, favor a post-2022 GLS 450 or a facelifted model (2023+) benefiting from more reliable electronics. The purchase of such a used vehicle must imperatively be accompanied by an extended warranty (such as Mercedes-Benz Certified) to protect against the exorbitant repair costs related to the air suspension or the 48V network.

Common issues

Dysfonctionnements du système MBUX (infodivertissement) Medium

🔧 Dès l'achat – 60 000 km

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

Vérifier l'historique des mises à jour logicielles et tester toutes les fonctions.

Problèmes du système mild-hybrid 48V (EQ Boost) High

🔧 40 000 – 100 000 km

💶 1 500 – 4 000 € (remplacement batterie 48V ou ISG)

S'assurer que les rappels liés au 48V ont été effectués par Mercedes-Benz.

Usure ou fuite des composants de la suspension pneumatique (AIRMATIC) High

🔧 80 000 – 150 000 km

💶 800 – 2 500 € par essieu (amortisseur, compresseur, valve)

Tester la montée/descente et l'absence de bruits anormaux ou d'affaissement.

Fuites d'huile moteur (couvre-culasse, carter, joints) Medium

🔧 70 000 – 120 000 km

💶 400 – 1 000 €

Inspecter visuellement le dessous du moteur pour toute trace d'huile.

Estimated maintenance costs

Oil change	£180 – 300
Timing chain	£1 400 – 2 800
Complete brakes	£750 – 1 400
Estimated annual budget	£1 100 – 2 300

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