This is the lunatic six-wheel Mercedes G 63 AMG 6x6, the largest and most extreme road legal SUV to ever hail from Mercedes' road car operations.

Produced on a limited basis – and at a price of £370,000 – the colossal double-cab pickup started life as an even more rugged military version of the G 320 CDI conceived and engineered for the Australian army and in operation since 2011.

This plush, leather-lined civilian version of the off-road vehicle has been conceived to appeal to some of Mercedes-Benz's most affluent clientele, and promises a vehicle without compromise, which is what we are in Dubai to find out.

It features six driven wheels, low range gearing, five differential locks and a tyre control system for its standard 37-inch wheels. Mercedes says it is "the last word in forward-thrusting power for the beaten track".

Unlike the military version of the G 320 CDI 6x6, which is fitted with Mercedes-Benz's 3.0-litre V6 diesel and is offered in outputs of up to 220bhp, the G 63 AMG 6x6 gets a twin-turbocharged 5.5-litre V8 from AMG with 536bhp. Torque is a 560lb ft – crucial in providing the shove required to haul the big four-seater’s considerable 3775kg kerb weight.

Mercedes' 7G-tronic seven-speed automatic transmission is fitted in place of the old NAG1 five-speed auto 'box found on the army version. Its transfer case can alter between a 0.87:1 high-range ratio for on-road driving and 2.16:1 low-range ratio for off-road conditions to all six wheels in a nominal 30:40:30 split. Power for the rearmost axle is supplied by an extra shaft. There are five electronic differential locks offering 100 per cent lock up of all six wheels, operated by three switches on the dashboard.

Relaying the engine's strong reserves to the ground are massive 37-inch wheels featuring a bead-plate design. They are shod with 12.5in-wide wheels.

At 5875mm in length, 2110mm in width and 2210mm in height, the G 63 AMG 6x6 is 1106mm longer, 225mm wider and 272mm higher than the G 63 AMG. Along with a 300mm increase in the wheelbase through to the middle axle at 3120mm, the front and middle axles have increased in width by 281mm each at 1790mm, requiring widened and lengthened carbonfibre guards to cover the huge wheels.