For most of its life, the Mercedes-Benz Unimog has been built around one simple idea — getting the job done. Whether that means working on farms, clearing snow, supporting emergency services, or heading into terrain most SUVs would rather avoid, comfort and luxury have never been at the top of the priority list.

To celebrate 80 years since the first Unimog prototype began testing in 1946, Mercedes-Benz Special Trucks has teamed up with Hellgeth Engineering to build the most luxurious version yet — a one-off U 4023-based show car that keeps the serious off-road hardware but adds more power, leather, LEDs and enough polish to make the old workhorse feel surprisingly at home in the luxury SUV world. Mercedes has even swapped the standard four-cylinder for a 300HP six-cylinder OM 936, making this the most powerful highly off-road-capable Unimog it has built to date.

And this is quite the birthday present for a vehicle that started life as a post-war agricultural machine. The first prototypes were developed in 1946 under the idea of a Universal-Motor-Gerät — essentially a universal motorized machine — before production moved from Boehringer to Daimler-Benz in 1951. Eight decades later, the basic philosophy hasn’t really changed; Mercedes has just decided that conquering the wilderness might be a little nicer with leather seats.

Luxury might be the headline here, but Mercedes-Benz hasn’t forgotten what makes a Unimog a Unimog. Underneath the new look is the U 4023, complete with portal axles, a highly flexible frame, selectable all-wheel drive and longitudinal and differential locks on both axles — the sort of hardware that has helped these things earn their reputation for going just about anywhere.

The bigger change sits under the bonnet. Mercedes has ditched the standard four-cylinder for a larger six-cylinder OM 936 producing 220 kW (300HP), with the transmission also revised to use the extra power and improve driving comfort. It might not sound outrageous compared with today’s 600HP-plus performance SUVs, but outright speed has never really been the Unimog’s game.

The exterior has also received plenty of attention, with matt-grey paintwork, chunky 20-inch aluminum beadlock wheels, and a new LED lighting setup giving the truck a surprisingly modern look. There’s even Mercedes-Benz Trucks’ MirrorCam system in place of traditional wing mirrors, using cameras and displays to improve visibility around a vehicle that isn’t exactly easy to lose in a car park.

And despite all the luxury touches, none of this has turned the Unimog into a soft-roader. It still looks like something you’d call when the luxury SUV gets stuck.

• Base vehicle: Unimog U 4023
• Engine: Mercedes-Benz OM 936 six-cylinder diesel
• Power output: 220 kW (300 hp)
• Drivetrain: Selectable all-wheel drive
• Axles: Portal axles, front and rear
• Differential locks: Longitudinal and differential locks on both axles
• Cab: Double cab, seating for up to four
• Mirrors: MirrorCam digital camera system
• Wheels: 20-inch aluminum beadlock wheels
• Lighting: LED headlights with a bespoke lighting signature
• Interior: Premium leather surfaces, contrast stitching, leather floor mats and ambient LED lighting

Climb into most Unimogs, and you’re usually greeted by an interior designed around durability and getting work done, but things are quite different here. Mercedes and Hellgeth have covered the double cab in premium leather, added ergonomically shaped seats with coloured stitching, leather floor mats and ambient LED lighting, with enough room inside for four people.

It’s still unmistakably a Unimog cabin, which is probably the right decision. Rather than trying to turn it into an S-Class on stilts, Mercedes has simply taken the familiar working environment and given it the kind of materials and finish you’d normally expect to find much further down the passenger-car side of the showroom.

Plenty of luxury SUVs can handle a muddy road or snowy driveway, but few start with a platform originally engineered for some of the toughest civilian and military jobs imaginable and then work backwards toward luxury.

As Franziska Cusumano, CEO of Mercedes-Benz Special Trucks, said: “With the luxury Unimog show car, we have realized our vision of combining the legendary robustness and off-road capability of the Unimog with an entirely new standard of comfort and engineering skills. This Unimog is a statement of innovation and passion.”

For now, don’t expect to walk into your local Mercedes-Benz dealer and tick the luxury Unimog box on the configurator. Mercedes describes this particular vehicle as a unique show car developed with Unimog specialist Hellgeth Engineering, rather than a new series-production model — although it feels like more than just something built to sit under the show lights.

The Unimog is undergoing real-world testing with a customer, giving Mercedes a chance to gather feedback for a possible future development stage. That makes things interesting, especially since Mercedes says international customers have been asking for a Unimog that combines its almost unmatched off-road ability with more power, comfort and distinctive styling.

Whether that eventually leads to a limited-production luxury Unimog remains to be seen, but it’s a fitting way to celebrate 80 years of one of Mercedes-Benz’s strangest and most capable creations. The Unimog can still crawl through mud, tackle difficult terrain and go places most luxury SUVs wouldn’t dare follow — now it can just do it with leather seats and ambient lighting.