Mercedes GLC X253 (2015 – 2023)

Reliability score : 7.8/10

The Mercedes-Benz GLC (X253 Generation) succeeded the GLK in 2015, marking a complete stylistic break with softer, more aerodynamic lines. Based on the MRA platform (shared with the C-Class W205), it established itself as one of the best-selling premium SUVs in the world. A major facelift occurred mid-2019, bringing the MBUX infotainment system, a revised light signature, and especially a new generation of diesel engines (transition from the aging OM651 to the modern OM654). The GLC shines with its supreme comfort, sound insulation, and 9G-Tronic gearbox, but requires a premium maintenance budget, particularly on versions equipped with Air Body Control air suspension.

✅ Strengths

Exceptional ride comfort (especially with Air Body Control)
Very high level of cabin sound insulation
Smooth and responsive 9G-Tronic automatic gearbox
Finish quality and interior presentation (especially post-facelift with MBUX)
Remarkable fuel efficiency of the OM654 diesel engine (post-2019)

⚠️ Weaknesses

Reliability and replacement cost of the air suspension (Air Body Control)
Capricious and expensive-to-repair AdBlue/SCR emission control system
OM651 diesel engine (2015-2019) rough and noisy under load
Reduced boot volume on plug-in hybrid (PHEV) versions
Possible creaks from the black lacquered plastic center console

🎯 Verdict

The Mercedes GLC X253 is an excellent premium SUV, but it requires a wise engine choice. If you are looking for a diesel, absolutely prioritize a facelifted model (post-mid-2019) equipped with the OM654 engine (GLC 200d, 220d, 300d). It is infinitely quieter, more fuel-efficient, and generally more reliable than the old OM651, despite persistent weaknesses in the AdBlue system. Avoid Air Body Control air suspension on high-mileage models, as its replacement will cost thousands of euros. A 2020 GLC 220d 4MATIC with conventional suspension is the ideal compromise.

Common issues

Problèmes du système AdBlue (SCR) High

🔧 80 000 – 150 000 km

💶 600 – 2 000 €

Utiliser AdBlue de qualité et effectuer des trajets longs régulièrement.

Dysfonctionnement du capteur NOx Medium

🔧 70 000 – 140 000 km

💶 400 – 800 €

Faire diagnostiquer rapidement les alertes moteur pour éviter des complications.

Encrassement ou défaillance de la vanne EGR Medium

🔧 100 000 – 180 000 km

💶 350 – 700 €

Conduire régulièrement sur autoroute pour aider au décrassage du moteur.

Encrassement du filtre à particules (FAP) Medium

🔧 120 000 – 200 000 km

💶 800 – 2 000 €

Privilégier les longs trajets pour permettre la régénération du FAP.

Problèmes de turbo (actuateur/wastegate) Medium

🔧 150 000 – 250 000 km

💶 1 000 – 2 500 €

Laisser le moteur refroidir quelques instants avant de couper le contact.

Estimated maintenance costs

Oil change	£110 – 190
Timing chain	£1 200 – 2 500 (si nécessaire, non routinier)
Complete brakes	£500 – 900
Estimated annual budget	£650 – 1 300

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