Mercedes SLC R172 (2011 – 2020)

Reliability score : 8.2/10

The Mercedes-Benz R172 began its career under the legendary SLK name in 2011, before undergoing a mid-cycle facelift in 2016 and being renamed SLC to align with the brand's new nomenclature (proximity to the Classe C). This roadster with a retractable hardtop (Vario-roof) represents the end of an era for Mercedes, combining the comfort of a coupe with the pleasure of a convertible. Positioned against the BMW Z4 and Audi TT, the SLC stands out for its 'Grand Touring' orientation rather than being purely sporty, although the AMG versions offer top-tier performance. The overall reliability of the R172 generation is very good, provided you avoid the early 4-cylinder petrol engines (M271). The transition to the SLC name in 2016 coincided with the introduction of much more reliable engines (M270

✅ Strengths

Retractable hardtop (Vario-roof) offering excellent soundproofing
Excellent reliability of post-2015 petrol engines (M270, M274, M276)
Superior ride comfort compared to the competition (Z4, TT)
Smooth and responsive 9G-Tronic automatic gearbox (on SLC)
Interior finish quality and aging of materials
Highly effective Airscarf system (neck heater)

⚠️ Weaknesses

High weight penalizing sporty agility
Disastrous reliability of the 1.8 engine (M271) on the SLK 200/250 (2011-2015)
Very reduced trunk volume when the roof is open (225 liters)
Dated infotainment system (Comand), even on the latest SLCs
Cost of parts and labor in the Mercedes network

🎯 Verdict

The Mercedes SLC (and the SLK R172 in general) is an excellent Grand Touring roadster. The buying verdict depends entirely on the year and the engine. We strongly advise you to target a model badged SLC (post-2016) or a late 2015 SLK equipped with the 2.0L engine (M274). These versions offer remarkable reliability, an excellent 9G-Tronic gearbox, and high-level driving pleasure. The V6 versions (SLC 43 AMG or SLK 350) are safe bets for lovers of fine mechanics. On the other hand, avoid the SLK 200 and 250 produced between 2011 and 2014 (M271 engine) unless the complete timing system (chain, tensioners, adjusters) has been recently replaced with an invoice. The diesel (250 d) only makes sense for very high-mileage drivers and presents risks of clogging and costly chain issues.

Common issues

Dysfonctionnement du mécanisme de toit Vario-roof (capteurs, vérins hydrauliques) High

🔧 80 000 – 150 000 km ou après 8-12 ans

💶 800 – 3 000 €

Vérifier le bon fonctionnement du toit et l'absence de bruits ou fuites avant achat.

Fuites d'huile moteur (électrovannes d'arbre à cames, boîtier de filtre à huile, pompe à vide) Medium

🔧 70 000 – 130 000 km

💶 300 – 800 €

Inspecter régulièrement le moteur pour toute trace d'huile, surtout sous le véhicule.

Problèmes de turbo (actuateur ou wastegate) sur moteurs M271/M274 Medium

🔧 90 000 – 160 000 km

💶 600 – 1 500 €

Tester la puissance du moteur et écouter les bruits anormaux du turbo à l'accélération.

Usure prématurée des silentblocs et rotules de suspension avant Low

🔧 60 000 – 120 000 km

💶 400 – 900 €

Écouter les bruits de claquement ou grincement sur routes dégradées et vérifier le jeu.

Estimated maintenance costs

Oil change	£90 – 160
Timing chain	£1 300 – 2 800 (si remplacement nécessaire, non routinier)
Complete brakes	£450 – 800
Estimated annual budget	£700 – 1 400

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