Mercedes GLA X156 (2013 – 2020)

Reliability score : 8.0/10

The Mercedes-Benz GLA (X156 Generation) marks the entry of the star brand into the highly competitive premium compact SUV segment. Based on the MFA platform (shared with the A-Class W176 and CLA), it resembles a raised sedan more than a true off-roader. Launched in late 2013, it received a facelift in 2017 (LED headlights replacing bi-xenons, redesigned bumpers, modernized multimedia screen, and Apple CarPlay/Android Auto integration). In terms of reliability, the GLA X156 is generally a good student, but it requires rigorous monitoring, particularly concerning its 7G-DCT dual-clutch gearbox and the emission control peripherals on diesel engines (which represent the majority of sales in Europe).

✅ Strengths

Dynamic design and low roofline (shooting brake look)
Paint quality and corrosion resistance
Remarkable fuel efficiency of diesel engines (OM607 and OM651)
Safe road handling, similar to a sedan
Effective 4MATIC system in snow and rain

⚠️ Weaknesses

Rear passenger space and boot volume (421 L) limited for a family
Uneven interior finish (hard plastics in lower sections, frequent rattling noises)
7G-DCT gearbox sometimes jerky at low speeds and during maneuvers
Imperfect sound insulation on diesel engines (especially the 2.1L OM651, very rough)
Poor rear visibility (reversing camera essential)

🎯 Verdict

The Mercedes GLA X156 is a relevant choice for those looking for the Mercedes badge and design in a compact format, without needing a large loading volume. For buyers targeting Diesel: The GLA 200 d (OM651) is the best power/reliability compromise, provided that the absence of cold chain noise and the 7G-DCT gearbox oil change history are scrupulously checked. The GLA 180 d is economical but its Renault-sourced engine requires timing belt replacement. Avoid diesel models if you only drive in the city (guaranteed clogging). In this case, opt for a GLA 200 petrol, which is more suitable and very reliable despite some thermostat weaknesses.

Common issues

Dysfonctionnement de la boîte automatique 7G-DCT (mécatronique ou embrayages) High

🔧 80 000 – 150 000 km

💶 2 000 – 4 500 €

Vérifier l'historique d'entretien de la boîte et la fluidité des passages de rapports.

Encrassement du FAP (Filtre à Particules Diesel) Medium

🔧 70 000 – 120 000 km

💶 800 – 2 000 €

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

Problèmes de vanne EGR (encrassement ou défaillance) Medium

🔧 60 000 – 100 000 km

💶 400 – 900 €

Une conduite souple et des nettoyages préventifs peuvent prolonger sa durée de vie.

Défaillance du système AdBlue (capteurs, pompe ou réservoir) Medium

🔧 80 000 – 140 000 km

💶 600 – 1 800 €

Utiliser uniquement de l'AdBlue de qualité et éviter de rouler avec un réservoir vide.

Estimated maintenance costs

Oil change	£90 – 160
Clutch	£1 600 – 3 200 (for 7G-DCT transmission)
Complete brakes	£280 – 550
Estimated annual budget	£650 – 1 300

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