Mercedes-Benz gave the world its first glimpse of the original ML in The Lost World, Steven Spielberg’s follow-up to Jurassic Park. And, just like the big-budget dinosaur sequel, the ML 4x4 failed to live up to expectations.

Struggling to shake off an initial reputation for patchy build quality, it was soon outpaced by the BMW X5 and Volvo XC90. By the time its replacement arrived in September 2005, it was struggling to find buyers.

Nevertheless, by then Mercedes had done what it should have done the first time round, and had built a decent, sturdy and impressively kitted-out 4x4. It was better looking and better built, and with its improved engines it could now go head to head with all comers.

Gone was the original ML’s separate chassis and body construction – the new model boasted a much more rigid, unitary body. Longer, wider and lower, it also had a sleeker appearance and weighed about eight stone less. The cosmetic changes also helped aerodynamics, which in turn boosted fuel economy and on-road refinement.

A new engine lineup increased the power of the 5 litre V8 petrol motor by 14bhp to 306bhp. It was joined by the impressive 3.5 litre V6 petrol with 272bhp and the new 3 litre V6 diesel producing 224bhp and a lusty 376 lb ft of torque, which became the most popular version. There was also a crazily powerful 6.3 litre, 510bhp AMG version, but that model deserves a review all of its own.

Noticeably quieter and more refined than the previous-generation diesels, the V6 makes the petrol options virtually redundant and promises acceleration to embarrass all but the most committed of petrol-lovers, together with economy nudging the 30mpg mark.

In response to strong diesel sales, Mercedes-Benz added two more oil-burners to the range this year: the 190bhp ML 280 CDI (in effect a detuned ML 320 CDI, as it has the same 3 litre diesel engine), and a mighty ML 420 CDI, with a 4 litre V8 producing 302bhp.

While most buyers will rejoice in the ML’s progress, there are two areas that may frustrate. First is the deletion of the seven-seat option. Despite competitive seven-seat offerings in the guise of the Volvo XC90 and Land Rover Discovery, Mercedes keeps the latest ML as a strict five-seater and instead directs larger families to its R-class and G-class models.

The second big change is the absence of a manual gearbox. Some towing purists may see this as a limitation, but the reality is that the standard seven-speed automatic will handle almost anything you throw at it. Combined with a column-mounted gear-selector, it makes for a leisurely but effective transmission system.

As usual, Mercedes offers new-car buyers a tempting list of options with which to personalise their vehicle. Larger wheels, chrome sidebars and aluminium radiator grilles are a matter of personal taste, but more universally desirable extras include air suspension, satellite navigation and fully electric seat adjustment.

When you are buying used, it is important to separate standard kit from options, and it’s just as important to ascertain which items command a premium. The Mercedes-Benz Comand system (cockpit management and navigation device), which controls the car’s audio and navigation equipment, is almost essential on secondhand examples, even though the sat nav system now looks dated when compared with newer, touchscreen systems.

The ML’s optional air suspension system comes into its own on the road, endowing the big Mercedes with almost limousine-like levels of comfort and vastly reducing body roll. Take the ML off road and, if the car is fitted with the optional Off-Road Pro pack, that same air suspension can be raised to increase the car’s ground clearance. With a full 2ft of wading depth, the committed ML driver is unlikely to be troubled by a summer flood.

Whether you intend to cruise, tow, mud-plug or just lug, the second generation of Mercedes-Benz ML is about as good as any luxury used 4x4 you can buy.

Body The ML’s wind resistance was reduced by a reduction in drag coefficient from 0.39 to 0.34

Gearbox Seven-speed auto gearbox is standard; operation is via a column change

Insurance Group 16-20, depending on model

Interior A step-up in quality compared with first-generation ML, but check carpets and seats for school-run damage

Off-road The optional Off-Road Pro pack includes lockable centre and rear differentials, a low-range transmission setting and adjustable air suspension

Safety Optional PreSafe system will pull seatbelts taut, adjust the front seats for an impact and shut the sunroof if an accident is predicted

Satellite navigation Optional extra worth having, but avoid paying more than a few hundred pounds for it

Seats Electric adjustment as standard; memory settings a desirable option

Servicing Variable service interval – check service history with servicing dealer to ensure authenticity

Tailgate 833-litre boot space with flat load lip and optional electric tailgate lifter

Wheels Avoid rims more than 19in in diameter or you’ll get a harsh ride

Vital statistics

Values Model Mercedes-Benz ML 320 CDI
Engine 2987cc, six cylinders, diesel
Power 224bhp
Transmission Seven-speed automatic
Fuel 29.4mpg (combined)
Acceleration 0-62mph: 8.6sec
Top speed 134mph
CO2 emissions 249g/km
Road tax band G (£400 a year/£210 a year if registered before March 23, 2006)
Cost new today £38,785

Mileage
(10,000/20,000/40,000)

2005 55
Trade £26,350 £25,050 £21,950
Retail £30,000 £28,750 £25,750

2006 06
Trade £27,950 £26,550 £23,950
Retail £31,750 £30,250 £27,750

2007 07
Trade £30,800 £29,250 £26,350
Retail £34,500 £33,000 £30,250

The one to buy
Mercedes-Benz ML 320 CDI SE Auto, 2005 55 with 40,000 miles.
Pay £25,750 at a Mercedes-Benz dealer or £24,500 privately

Or for similar money
2005 05 Toyota Land Cruiser 4.2 TD auto
2005 55 Land Rover Discovery 2.7 Td SE auto
2006 06 Volkswagen Touareg 3.0 V6 TDI Altitude auto
2006 06 Volvo XC90 2.4 D5 SE Geartronic
2006 56 BMW X5 3.0d SE auto