There are 187bhp and 221bhp 3.0-litre diesels, plus a 302bhp 4.0-litre unit. High-performance 383bhp 5.5-litre and 503bhp 6.2-litre petrol engines are also available. Even the lowest-powered engine is adequate, and only the power-crazed will stray beyond the 221bhp 3.0-litre diesel.
The M-Class is extremely composed on all but the bumpiest of roads, when the ride becomes jittery. All this makes it a great motorway cruiser, but compromises its back lane ability. The handling is reasonably engaging and weights up at speed. Its off-road capabilities are extremely limited.
There’s no road noise, virtually no interference from headwinds at motorway speeds and all engines, apart from the highest-powered ML63 AMG unit, are audible only when being stretched to their limits.
Even with Mercedes' reputation, a generous discount should be possible. Its residual value will fare better than most, but will still suffer as large 4x4s fall out of favour. Running costs are high: all cars fall into the highest VED road tax and company car tax bands, while the most frugal returns an average fuel consumption of just more than 30mpg.
The cabin is mostly luxurious, but is slightly compromised by some hard plastic trim low down. Mercedes traditionally performs well in the JD Power Customer Satisfaction survey, but is only a midfield performer in the What Car? reliability supertest.
Front, side and curtain airbags come as standard equipment, along with anti-whiplash head restraints, pre-tensioning seat belts and a full range of electronic braking and stability aids. All versions have an alarm and immobilisation system to deter thieves.
Drivers can easily get comfortable, thanks to a good range of steering wheel and seat adjustment. The dashboard is sensibly laid out and everything is within easy reach, including the gear selector, which is sited on the steering column.
The M-Class offers ample head- and legroom for four, while a centrally seated rear passenger has only a low tunnel between their feet. The boot is large and sensibly shaped. Flip the rear seat bases forward and you can create a bay that’s big and flat, while a system to secure smaller loads is also available.
All versions have cruise and climate control, four electric windows, automatic transmission, front and rear parking sensors, a powered tailgate, rain-sensing wipers and Bluetooth connectivity. Sport trim adds chrome and steel detailing inside and out, sports front seats, and Alcantara and leather trim options.