Mercedes Classe B W245 (2005 – 2011)

Reliability score : 6.8/10

The Mercedes-Benz B-Class (W245) was introduced in 2005 as a premium compact MPV, marketed by Mercedes as a 'Sports Tourer'. It shares its unique 'sandwich floor' architecture with the A-Class (W169). This design places the engine and transmission at an angle, allowing them to slide underneath the passenger cabin in the event of a frontal collision. While this provides exceptional interior space and top-tier safety for its footprint, it makes mechanical access notoriously difficult, significantly inflating labor costs for repairs. The model received a mid-life facelift in 2008, which addressed early rust issues, updated the infotainment (COMAND), and introduced BlueEFFICIENCY models. This guide focuses heavily on the popular OM640 diesel engines, while exhaustively covering the petrol and

✅ Strengths

Exceptional interior space-to-footprint ratio thanks to the sandwich floor.
High seating position offering excellent visibility (SUV-like feel).
Top-tier crash safety for its era.
High-quality interior materials, especially on post-2008 facelift models.
OM640 diesel engines are capable of very high mileages (300,000+ km) if maintained.

⚠️ Weaknesses

Exorbitant labor costs for simple repairs (starter motor, glow plugs, alternator) due to engine bay packaging.
Autotronic CVT transmission is fragile and expensive to repair (TCU failures).
Glow plugs on diesels frequently snap in the cylinder head.
Lamella panoramic roof (louvred roof) is highly prone to jamming, breaking, and leaking.
Pre-2008 models suffer from significant rust issues on doors and tailgates.
Firm ride quality, especially on models with larger alloy wheels.

🎯 Verdict

The Mercedes-Benz B-Class W245 is a brilliant concept compromised by its own packaging. The sandwich floor provides amazing space and safety, but turns routine maintenance into a mechanic's nightmare. For Diesel buyers: The OM640 is a robust engine, but you must buy a post-2008 facelift model with a manual transmission, and you must verify that the glow plugs and injectors have been recently serviced. Avoid the Autotronic CVT unless you have proof of meticulous maintenance and a recent TCU repair. If you drive mostly in the city, avoid the diesel entirely due to DPF and EGR issues, and opt for a B 180 petrol instead.