Mercedes Classe A W177 (2018 – 2025)

Reliability score : 8.2/10

The fourth-generation Mercedes-Benz A-Class (W177 for the compact hatchback, V177 for the sedan) marks a major technological breakthrough with the introduction of the MBUX infotainment system. Positioned as the benchmark premium compact against the Audi A3 and BMW 1 Series, it offers significantly improved finish quality compared to the previous generation (W176). A facelift occurred in late 2022, bringing mild hybridization (48V MHEV) to the petrol engines, the removal of the central touchpad, and a software update. Although global demand is shifting towards petrol and hybrid, the diesel offering (which is of particular interest here) remains one of the most accomplished on the market, with highly efficient engines (the reworked Renault-sourced OM608, then the excellent 100% Mercedes OM65

✅ Strengths

Diesel offering (OM654q) among the best on the market: quiet, torquey, and extremely fuel-efficient
Spectacular onboard technology and MBUX system
Significantly improved interior finish quality compared to the W176
Very sound road handling and suspension comfort (especially with adaptive damping)
Exceptional aerodynamics benefiting sound insulation on the highway

⚠️ Weaknesses

Frequent electronic bugs on 2018-2019 models (screens, driving aids)
7G-DCT gearbox (on smaller engines) sometimes hesitant and causing jerks in urban driving
Average rear passenger space and boot volume for the category
Very high maintenance costs within the Mercedes network
Cylinder head issue on the 2.0L petrol engine (M260) in early years

🎯 Verdict

The Mercedes A-Class W177 is a highly desirable premium compact that has successfully corrected the comfort and finish flaws of its predecessor. If you are looking for a diesel, it is an excellent choice. The small 1.5L (180d until 2020) is an ultra-reliable workhorse, ideal for tight budgets. However, the 2.0L diesel (OM654q in 200d or 220d) is the true gem of this range: it offers superior driving pleasure, remarkable reliability, and negligible fuel consumption on the highway. Avoid 2.0L petrol models (220/250) from 2018-2019 without warranty due to cylinder head risks. Prioritize a post-2020 model to avoid the early electronic bugs of the MBUX system.

Common issues

Dysfonctionnements du système AdBlue/SCR (capteurs NOx, pompe, cristallisation) High

🔧 80 000 – 150 000 km

💶 700 – 1 500 €

Vérifier l'historique d'entretien du système AdBlue et éviter les trajets courts.

Encrassement du filtre à particules diesel (FAP) Medium

🔧 100 000 – 180 000 km

💶 200 – 500 € (nettoyage/régénération forcée)

Privilégier les longs trajets réguliers pour permettre la régénération du FAP.

Encrassement ou défaillance de la vanne EGR Medium

🔧 100 000 – 180 000 km

💶 600 – 1 000 €

Un nettoyage préventif peut prolonger sa durée de vie. Surveiller la perte de puissance.

Bugs et dysfonctionnements du système d'infodivertissement MBUX Low

🔧 Variable

💶 0 – 300 € (mise à jour logicielle, hors garantie)

S'assurer que le véhicule a bénéficié des dernières mises à jour logicielles.

Estimated maintenance costs

Oil change	£90 – 160
Timing chain	£1 200 – 2 500 (si remplacement nécessaire, non routinier)
Complete brakes	£350 – 650
Estimated annual budget	£650 – 1 200

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