By: Dave Abrahams
Stuttgart, Germany - The beetle-crusher boys at the G-Series development centre in Graz, Austria created a problem for themselves when they built the Mercedes-Benz G63 6x6. With all due respect - how do you top that?
Here's how - the G500 4x4². The basic recipe is pretty simple - two of the three portal axles from the 6x6 on a newly-developed variable chassis with double dampers and a big can of whup-ass, courtesy a 310kW direct-injection four-litre biturbo V8, with a series-production G-Class body on top, garnished with carbon-fibre add-on body trim and 22-inch rims wearing 325/55 rubber.
But the devil, as they say, is in the details and the details in this case are gourmet ingredients from the Designo range of interior options, giving this show special a luxury interior on a par with a premium sedan.
The newly developed V8 has its dual turbos in the V instead of on the outside, which traps a lot of excess heat (they don't call it the 'hot inside V' layout for nothing) but results in a compact engine design with optimum response and low exhaust emissions.
Dual side pipes on either side not only give the 4x4² a voice of unmistakeable authority, they also radically improve the departure angle because there are no silencer boxes hanging below the rear body.
PORTAL AXLES
But, like the 6x6, the 4x4² concept is all about its Unimog-style portal axles; the wheels are not at the centre of the axle as in conventional rigid axles but much further down, thanks to portal transmission gears at either side - which increases ground clearance from the standard G500's 210mm to a towering 450mm and fording depth from 600mm to 1000mm.
Approach angle is up from 36 to 52 degrees, departure from 27 to 54 and break-over angle from 21 to 47 degrees - and yet all the suspension mounts and steering geometry stay the same, while the reduction gears in the hubs reduce impact loads on the entire drivetrain.
Suspension deflection is modulated by two spring/damper struts running in parallel on each wheel, which is commonplace on off-road racing vehicles but, in this case, one damper in each pair is adjustable from the cockpit to either SPORT or COMFORT settings, while the other has electronically controlled adjustable damping that varies according to the current driving situation.
LIKE A SPORTS CAR
In extreme situations such as emergency lane changes, the system automatically switches over to the SPORT setting for maximum stability, while the comfort setting allows maximum wheel deflection for off-road traction.
The portal axles are also 299mm wider than the standard G-Class running gear so, with 22-inch rims and the SPORT suspension settings activated, the 4x4² corners like a sports car on tar.
For serious beetle-crushing, in addition to permanent all-wheel drive, a low-range transfer case and three differentials lockable 'on the fly', the G-men from Graz have made provision for 18-inch beadlock rims wearing 37 x 12.5 x 18-inch mud/terrain tyres.
And despite all that, if you still manage to bang the chassis into a piece of real estate, there are stainless-steel underbody guards fore and aft to protect the important bits from marauding rocks.
DRESSED FOR SUCCESS
The 4x4² wears a G65 AMG front bumper, a carbon-fibre trim element with integral LED light strips above the windshield and partially painted wheel-arch flares - also made of the light stuff - all round, but the really fancy trim is inside.
The seat bolsters and head restraints are upholstered in black leather with whiter contrast stitching, as are dashboard, centre console and door armrests. The seat surfaces and door panels are trimmed with Dinamica microfibre synthetic suede in a quilted pattern, while more Dinamica provides the body-pillar and roof liners.
The guys from Graz call the G 500 4x4² a near-series concept; whether and when it will go into production, they say, depends on the reaction when the concept goes on show.