Mercedes-Benz R 320 CDI 2006 Review

Launch Review

2006 Mercedes-Benz R 320 CDI

What we like
Fuel efficient and torquey engine
Smooth seven-speed auto
Comfortable ride

Mercedes calls its new all-wheel drive R-class a Grand Sports Tourer and given its size and performance you could easily agree with the Grand and Sports parts. Now with the addition of a diesel variant, it also becomes a very efficient tourer as well.

The new diesel R 320 CDI sits in the middle of the range of six-seater wagons but with a starting price of $85,900 (for the standard wheelbase version) it carries a modest $3000 premium over the entry-level petrol V6 R 350 (To read CarPoint's R-Class launch review click here).

And as we discovered on the recent launch through the Alpine areas of Victoria, it is a small price to pay for what could mean significant fuel savings.

While the V6 and V8 petrol versions are no doubt comfortable and pleasant conveyances for long distance touring, with petrol prices continuing to rise, they are also relatively expensive options for longer journeys. According to the official ADR 81/01 combined fuel consumption test, the 200kW/350Nm 3.5-litre V6 uses an average 11.5lt/100km while the 225kW/460Nm 5.0-litre V8 sups petrol at the rate of 13.3lt. This compares to just 9.3lt for the 165kW/510Nm 3.0-litre V6 turbodiesel R 320 CDI.

As a static dynometer test, these figures tend be rather conservative when compared to real world figures. So when CarPoint managed to achieve an average consumption for the diesel R-class of 10.5lt/100km over 200km of enthusiastic driving through some serious mountain terrain we were pleasantly surprised. This sort of frugality certainly makes the diesel option appealing.

But the diesel engine offers far more than just fuel savings as its abundance of low to midrange torque make it eminently suitable for hauling the 2200kg-plus bulk of the R-class.

At idle, the engine is supremely quiet and refined and a firm prod of the right foot gets it off the line in a smooth and none too tardy fashion. While it is not lacking in bottom end grunt, the engine really hits its stride above 2500rpm and will continue to pull through to 4000rpm without losing its breath.

The engine is mated to a supremely smooth seven-speed automatic transmission and on the winding hilly roads it was quick to respond to the throttle with almost imperceptible shifts. It’s a smart gearbox and even without the driver’s input has the ability to always keep the engine in its power zone.

Despite the car's size and weight, it is actually quite enjoyable to punt along with enthusiasm. While the ride is firm, it never feels uncomfortable with plenty of compliance in the suspension to soak up the worst of most roads.

At the same time, it feels stable and solid and sits fairly flat on the road through corners and doesn't roll as much as you might expect with superb grip from the 235/65 17-inch rubber.

When things do get overly slippery, the ESP and traction control are calibrated to intervene in a relatively subtle manner so as not to kill the moment.

The only downside to the handling is the steering which, although well weighted and progressive, feels a little remote in terms of feedback. Alas this is not something the R-Class has on its own in the current Benz line-up.

Grand, sports and tourer; all boxes ticked for functionality and efficiency – especially now there’s an excellent and remarkably fuel efficient turbodiesel option… That said, we'd still call it a luxury all-wheel drive peoplemover.