BUYERS GUIDE - WAGONS MEDIUM
The M-Class, fitted with the optional off-road package that included height-adjustable air suspension, low-range gearing and a proper spare wheel was the last ‘Benz wagon that was useful on and off road
The last ML, third generation model, was released in mid-2012. Significant dynamic safety and fuel consumption benefits were highlights of the last MLs.
ECO start/stop function came as standard, as did the latest seven-speed 7G/TRONIC PLUS automatic transmission with a new fuel-economy-sensitive torque converter, friction-optimised bearings and a transmission oil thermal management system.
The previous ML 300 CDI V6 diesel was replaced by a thrifty 2.5-litre four-cylinder with a claimed combined consumption of 6.4 L/100km – some 30 percent lower than that of the previous model.
The ML 350 BlueTEC 4MATIC featured a revamped 3.0–litre V6 with even better performance and a claimed combined fuel consumption figure of just 7.3 L/100km.
Thanks to AdBlue emission control technology both diesel models met the EU6 standard slated for European introduction in 2014.
The ML 350 4MATIC BlueEFFICIENCY petrol-engine model had a third-generation direct petrol injection system and a claimed combined consumption of 8.9 L/100km – 23 percent lower than that of the previous ML 350 4MATIC model.
What you got
Even the standard version M-Class offered a high level of comfort, dynamic on-road handling and off-road capability. For the first time, the M-Class chassis with steel-spring suspension featured selective damping. Power steering was all-electric.
Standard kit included 4MATIC permanent all-wheel drive, 4ETS electronic traction control and an off-road button which activated a special off-road driving mode. Hill start assist and Downhill Speed Regulation (DSR) took care of steep grades.
The optional ON&OFFROAD package for the new M-Class had six driving modes for optimising dynamics and handling. The driver could select from one automatic mode, two special off-road modes and three on-road modes using a rotary control in the centre console.
The ON&OFFROAD package comprised a bash palte, two-stage transfer case with 3:1 reduction gear, an inter-axle differential lock and enhanced AIRMATIC air suspension that allowed a maximum ground clearance of 285mm and a fording depth of 600mm.
Optional active roll stabilisation used active anti-roll bars on the front and rear axles.
Nine airbags were activated on demand in accordance with the accident type and accident severity.
The standard equipment package included a drowsiness detection system, tyre pressure loss warning, adaptive brake lights and Brake Assist (BAS). Active assistance systems such as Active Lane Keeping Assist and Active Blind Spot Assist were standard on all models except ML 250 BT.
Available wheels ranged from 18-inch through to 20-inch and 21-inch AMG wheelscould be fitted to emphasise the sporty look of the new M-Class.
The ML interior offered more elbow room than its predecessor (an extra 34mm in the front and 25mm in the rear, power front seat settings, adjustable rear seat backrests and through-loading for transporting skis.
The M-Class came as standard with COMAND Online multimedia system, with a high-resolution 17.8 cm colour display and internet access in the M-Class for the first time. Also standard for all M-Class models was a reversing camera.
Our evaluation vehicle was a 250 four cylinder, which proved to be a great performer. This engine began life in the Sprinter van, so it’s designed to haul plenty of weight around. Unfortunatley, the test vehicle lacked an off-road package, so our testing was confined to made surfaces, but we did confirm its brilliant economy, with an average of 7L/100km.
We checked out the high-performance V6 diesel in the previous model (see below).
Mercedes-Benz’ three-litre V6 – the world’s first all-aluminium-casting V6 diesel – powered the pre-2011 Jeep Grand Cherokee CRDV6 and the Mercedes-Benz ML300 CDI
and ML350 CDI models. The move to the V6 followed the successful sharing these then-Daimler-Chrysler companies had with the now-superseded five-cylinder, 2.7-litre CDI that powered the original ML270.
The three-litre V6 diesel had an aluminium block with cast-in, grey-iron cylinder liners. Aluminium was also used for the cylinder heads, cylinder head covers, pistons, coolant pump, sump and charge pressure distributor. Components in the fresh and charge air ducting systems, silencer and engine shrouding were plastic.
Claimed weight of the new engine was almost the same as that of the outgoing five-cylinder unit and gave the V6 engine a power to weight ratio of 0.8kW/kg.
The 24 intake and exhaust valves were operated by a chain-driven overhead camshaft on each cylinder bank, via roller rocker arms with hydraulic valve clearance. The same chain drove the balance shaft and the high-pressure pump for the fuel injection system. A separate roller chain was used to drive the oil pump.
The V6 featured exhaust gas recirculation, third-generation common-rail direct injection, piezo injectors, a variable-nozzle turbocharger and an intercooler. It delivered claimed outputs of 140kW and 440Nm in the ML300 CDI and 165kW and 510Nm in the ML350 CDI. Buyer confusion was caused by the petrol V6 model’s designation as ML350.
The petrol engine had outputs of 200kW and 350Nm, while the range-topping petrol V8 ML500 had 285kW and 530Nm. For those who just can’t have enough grunt the AMG V8 put out 375kw and 630Nm!
One of the best features of the second and third generation MLs was the 7G-TRONIC transmission. All our testers loved the almost-seamless shift quality of the box, but all detested the DIRECT SELECT control lever.
A selector stalk on the steering column replaced the conventional automatic selector lever in the centre console. It was slower to use than a central-tunnel lever and was easily mistaken for an indicator stalk by drivers accustomed to right-side blinker wands: a right-turn indicator action on the ‘Benz lever sent the transmission into neutral.
That was tricky enough, but buttons behind the steering-wheel spokes performed manual shifts, unless you happened to be turning the wheel at the time and your fingers couldn’t reach the buttons! If ‘Benz had to use that shift method why didn’t the designers put in gearshift ‘paddles’ that stay in the quarter-to-three position on the column? A very nice transmission spoiled by complicated controls.
The Mercedes-Benz AIRMATIC air suspension we evaluated was part of the optional Off-Road Pro engineering package that included a 2.93:1 low range gear set in the transfer case, electronically lockable front, centre and rear differentials, with manually lockable centre and rear override, and underbody protection.
AIRMATIC enabled the vehicle level to be raised in three stages, by 30, 80 and 110mm. It worked with an adaptive damping system (ADS) that controlled damper response, via solenoid valves in the shock absorbers.
A so-called ‘skyhook’ algorithm controlled the damping forces at each wheel, so that, for example, the two front wheels could be damped more heavily than the rear wheels to reduce ‘dive’ when braking.
Driving conditions were worked out by the suspension electronic control unit, with inputs from a steering angle sensor, three body-mounted acceleration sensors, the speedometer, the electronic stability program (ESP) and the brake pedal switch. The ECU calculated the most appropriate damping forces and dialled up one of four bump and rebound settings in the shock absorbers.
There were also two shocker control buttons, allowing the driver to select damper forces and air spring rates manually.
Although the ML300 could be raised to a ground clearance level that let it follow a Range Rover Sport off road, the ‘Benz never felt at home in difficult off-road terrain. The air springs rode very harshly on the highest setting, giving the vehicle a rough ride and making the traction control and hill descent systems work overtime.
Sadly, the ML was replaced by the much softer GL range, with silly wheels and on-road tyres, and a run-flat spare or no spare at all. This kit made it unsuitable for any serious bush driving, so we lost interest in reporting on it.
First generation ML
A well-serviced five-cylinder diesel ML270 makes a good used purchase. Petrol versions drive well, but are thirsty. Parts and servicing
are very expensive.
There are not many after-market bits for the M-Class, because most three-pointed-star 4WDs stay on formed surfaces. That doesn’t mean they can’t go seriously bush, but air-suspended models have much better ground clearance than steel-spring models.