Overview What is it?

The door handle button, the headlight washer nozzles, the sun visors and the spare wheel cover. That’s a comprehensive list of the parts that have been carried over from the old G-Class. Apparently there’s a bracket underneath that also has the same part number as before, but even the engineers can’t remember quite where it is. Everything else – everything – is new.

About time, really. The old G had been around since the dawn of the motor carriage (well, 1979), an old soldier still refusing to desert its post.

That post is off-roadability. Surely Mercedes must have been tempted to take the new one in a more urban direction, since that’s the landscape the G seems most able to conquer? “Not at all”, says Gunnar Guthenke, the G-Class’s boss, “above all it had to be authentic, so there were three elements we absolutely had to keep: the super-tough ladder chassis, the three locking differentials and the low range gearbox”.

Reassured? Off-road is still the focus, because authenticity comes from ability. But Guthenke also knew things had to change, “again we identified three key areas: to drastically improve interior comfort, to drastically improve ride comfort and to further improve off-road behaviour”.

The outcome is unusual: a full-length ladder frame chassis that incorporates independent front suspension with tightly packaged double wishbones, surmounted between the uprights by a chunky brace. The body is 55 per cent stiffer, all the components tucked within the ladder frame for protection. The chassis itself is actually heavier than before, but overall the G is 170kg lighter.

It’ll wade water 100mm deeper than before (now 700mm), can lean over to 35 degrees and climb and descend 45 degree slopes. There’s no height adjustable chassis because Mercedes doesn’t believe the suspension airbags are durable enough in extreme conditions. In the UK only one engine will be available initially, the one that accounts for nearly two-thirds of global sales. Not the diesel as that comes next year, but the AMG twin-turbo V8. It’s the 4.0-litre from the AMG GT R, with 577bhp and 626lb ft. In left-hand drive markets there’s also a G500 using a detuned 416bhp/450lb ft version of the same engine.