Mercedes-Benz now has an SUV worth bragging about. While previous generations of the M-Class were saddled with an underwhelming interior and lacked for quality feel compared to other models in the Mercedes stable, the new ML is vastly superior in virtually every metric. It鈥檚 grown up, gone to finishing school and adopted a more polished persona. It鈥檚 classy, sensible and very, very refined. It鈥檚 so refined, in fact, that we were constantly reminding ourselves that our ML 350 Bluetec tester was, indeed, a diesel. Toorak: yes. Tractor: not at all. Quality: Tight shutlines, premium plastics and solid switchgear abound in the ML鈥檚 interior. It鈥檚 solid, that鈥檚 for sure, and the only negative we could find was a slightly squeaky lid on the centre console box. The use of leather is also a highlight. Not only is the seat upholstery supple, but the application of stitched leather to the upper dash and door trims imparts a premium feel to the cabin. Comfort: No complaints about the driving position.

The instruments are clear and easily legible, and the migration of the 17.8cm infotainment display to the top of the dash makes it easier to keep an eye on things like the sat-nav and radio. The electrically-adjusted front seats (standard) are a little lacking in side-bolstering, but are comfortable and offer good lower back support. There鈥檚 plenty of space for two adults to sprawl in the back. There鈥檚 also space for a third person, but the sculpting of the rear bench means it鈥檒l be less comfortable for whoever鈥檚 sitting in the middle. However, with generous legroom, plenty of headroom, a big fold-down centre armrest and a pair of rear air outlets, the back seat of the ML is certainly accommodating. Equipment: As standard on the ML 350 Bluetec, you get powered front seats, a power-adjustable steering column, folding electric wing mirrors, dual-zone climate control, leather upholstery, cruise control, a speed limiter, trip computer, parking sensors and a reversing camera.

Bi-xenon headlamps with automatic high-beam are also standard on the ML 350 Bluetec. The COMAND APS infotainment system incorporates a radio, CD/DVD player, sat-nav, internet functionality and a 10GB onboard music storage drive. Bluetooth telephony and audio streaming is also standard, as is a USB audio input for portable music players. COMAND, it must be mentioned, is starting to look a little dated and is missing the outright intuitiveness of systems used by Lexus, BMW and Audi. It is perhaps the one aspect of the M-Class鈥?interior that could still do with improvement. Storage: Space is not a problem in the ML 350鈥檚 boot. Seats up, there鈥檚 a sizable 690 litres of available luggage room. Flip up the rear squabs and fold the backrest down, and you get a flat-floored area measuring in at a huge 2010 litres. You also get a retractable cargo blind with in-built cargo-net. Driveability: The ML 350 Bluetec鈥檚 3.0 litre turbodiesel V6 is perfectly suited to hauling around a 2.2-tonne SUV.

Laden with torque (620Nm) and with 190kW of power, the ML鈥檚 diesel six is muscular enough to take it to triple digit-speeds in just 7.4 seconds. The seven-speed 7G-tronic automatic is a slick unit too. Shifts are smooth and slur together seamlessly during normal driving, and the ratios keep the engine well within its comfort zone. There鈥檚 a pair of shift paddles behind the steering wheel should you feel the need to take control of the gearchanges, but don鈥檛 bother. There鈥檚 no point trying to second-guess this transmission, it鈥檚 that good. Refinement: We were surprised - nay, amazed - at the refinement of the ML 350 Bluetec鈥檚 powertrain. Modern diesels are rapidly getting quieter and smoother, but this V6 is less coarse than even some petrol engines. From the cabin and with the engine idling, there鈥檚 only the scarcest hint that there鈥檚 internal combustion happening on the other side of the firewall. Give the engine some revs and there鈥檚 no gravelly note either.