MERCEDES-BENZ Australia admits it is moving into uncharted waters with the new R-class "crossover" wagon.

Fitting between the E-class station wagon and the M-class 4WD, the six-seater R-class is aimed at people who want the versatility of a wagon but not quite the off-road ability of a 4WD.

However, the company quietly believes that, like the B-class, its newest entrant will prove popular even if it does not fit into an easily identifiable segment.

At present, Mercedes-Benz offers 18 body styles and around 65 variants in its passenger vehicle line-up in Australia, and the R-class further muddies the waters.

However, it is among the first of a new wave of specifically targeted "crossover" vehicles emerging out of Europe and Japan that further blur buyer boundaries.

Mercedes describes the car as a 4+2 seater that is bigger than an E-class wagon but shares platform architecture with the M-class. It claims the car eclipses both conventional people-movers and SUVs because of its versatility, combined with all-wheel drive.

Based on the Vision GST concept car first unveiled in 2002, it is essentially designed for the North American market and remains largely faithful to the GST’s overall design – except for the deletion of "suicide" rear doors which featured on the concept car.

A striking grille with long, horizontal louvres and steeply sloping bonnet dominates the front end. Mercedes also claims the arching roofline between the front and rear pillars offers a coupe-like profile.

Six variants will be available in Australia, with a choice of two petrol or one common-rail turbo-diesel engine in either short- (2980mm) or long- (3215mm) wheelbase guises.

The model range consists of the 200kW/250Nm 3.5-litre V6 R350, 165kW/510Nm 3.0-litre turbo-diesel R320 CDi and 225kW/460Nm 5.0-litre V8 R500. A high-performance 375kW/630Nm 6.2-litre V8 R63 AMG model variant will join the line-up later this year.

Among the standard equipment is Mercedes’ 7G-Tronic seven-speed automatic transmission, permanent all-wheel drive, rear-axle air suspension, traction control, stability control, brake assist, a collision avoidance system, tyre-pressure monitoring, parking radars, 17-inch alloy wheels, an eight-speaker six-stacker CD changer, climate-control air-conditioning, rear "executive" seats, a multi-function steering wheel, rain-sensing windscreen wipers and dual front, side and curtain airbags.

The R500 adds 18-inch alloys, leather upholstery, electric front seats, automatic steering wheel adjustment, heated front seats, satellite navigation, electrically folding and automatically dimming exterior rearview mirrors, adaptive damping, a Harman Kardon surround sound stereo, a "Touring" package, Thermotronic climate control and a centre console for the second row.

Up front is a double-wishbone suspension set-up with a forged aluminium high-mounted upper wishbone. The front axle, steering gear, engine and transmission are mounted on an integral sub-frame of high-strength sheet steel. The rear suspension is an aluminium/steel four-link design mounted on a sub-frame.

Measuring 4922mm long, even the short-wheelbase model is big – the long-wheelbase version adds another 208mm.

The large footprint allows for an impressively roomy cabin. There is 920mm between the first- and second-row seats and the second row can be individually adjusted, increasing seat space to as much as 990mm. The four rear seats also fold flat individually, allowing for the load area to be increased to as much as 2057 litres.

Loading and unloading is made easy through a flat luggage area measuring 2.2m in length. The tailgate can be ordered with remote control opening and closing for an extra $1550.

An $8500 Touring package and $8500 Sports package are also available.

The Touring package, which is standard on the R500, includes burr walnut interior trim with chrome highlights, a compass, electric rear vent windows for the third row of seats, electric front seats, leather upholstery, multi-contour backrests for the front seats, a rear centre console between the second-row seats, aluminium window frames and additional interior lights.

The sports package offers 19-inch alloys, blue-tint glass, special instrument cluster, stainless steel pedals, electric sports seats in Alcantara and leather- and-aluminium trim highlights.

Mercedes-Benz spokesman Toni Andreevski said initial volume expectations are conservative as the R-class is introducing the "crossover" concept to Mercedes buyers. The forecast is for about 350 R-class sales annually with the R320 CDi and R350 V6 being the volume sellers.

Mercedes-Benz expects the turbo-diesel models to be the wildcard, as it believes the combination of diesel with all-wheel drive and the interior packaging will appeal to SUV owners looking for something different.