Durability testing of the upcoming Mercedes-Benz EQG has begun in earnest, with a series of prototypes being pressed into duty at the halfway point of a four-year engineering programme.
Originally previewed in concept car form at the 2021 Munich motor show, the new electric version of the Mercedes-Benz G-Class is set to become Mercedes-Benz’s ninth dedicated electric model when it goes on sale in the UK in 2024, kicking off a whole new chapter of electrification for the traditional hardcore off-roader, a mainstay of the German car maker’s line-up since 1979.
The EQG is also earmarked to act as a technological spearhead for Mercedes-Benz’s newly created G (for Geländewagen) sub-brand, promising what its CEO, Emmerich Schiller, describes as an “unparalleled combination of luxury and off-road ability for electric vehicles”.
“From the start, it was decided the electric G-Class should be at least as good as the internal combustion engine model both on road and off road. We didn’t want to compromise on capabilities,” he says.
Based on the latest iteration of the G-Class – codenamed and known within Mercedes-Benz engineering circles as W463 – the EQG builds off a modified version of the steel ladder-frame chassis used by internal-combustion-engine models, alongside which it is planned to be produced at long-time partner Magna Steyr in Graz, Austria.
Early road-going prototypes confirm the EQG will retain the same characteristic square-rigged exterior styling as other existing G-Class models. Although disguised, they feature standard body panels together with a number of small but unique details, as hinted at on the earlier concept, including a new-look front bumper and a blanked-off grille.
“We have two skateboards with the same hat on top,” says Schiller, in reference to the ladder-frame chassis and familiar G-Class styling. “As with the internal-combustion-engine models, the body is connected to the ladder frame at eight points.”
Like Mercedes-Benz’s other EQ models, there is no front luggage compartment or frunk. The charging cable will be able to be stowed in a lockable box similar to that previwed by the concept, mounted in the place traditionally taken by the spare tyre on the sideways-opening tailgate.
At the centre of the EQG’s technical development is a new electric drivetrain consisting of four electric motors – one powering each individual wheel. Unique among Mercedes-Benz’s current line-up of EQ models, it mirrors that of the SLS E-Cell produced by Mercedes-Benz’s AMG performance car division in limited volumes in 2013.
The four-motor layout, also used by US electric vehicle start-up Rivian for its R1 SUV and pick-up, is aimed at providing the EQG with what Schiller describes as an unrivalled combination of off-road performance and refined on-road qualities.
“There were intensive discussions surrounding the four-motor layout. It is incredibly complex. It is also very expensive. But with two electric motors you have differential locks, which means a combination of electronic and mechanical systems. With three motors – one up front and two on the rear axle, you don’t get the full performance in off-road conditions,” he says.
Mercedes-Benz is holding back on disclosing power and torque figures for its latest electric model. However, Schiller hints there will be varying models with differing outputs, including an AMG flagship claimed to provide a level of on-road performance, including straight-line acceleration, to match the existing 577bhp twin-turbocharged 4.0-litre V8 petrol engine powered Mercedes-AMG G63 4Matic.
The front electric motors are mounted low at each side within the axle. The rear electric motors are integrated more inboard within a newly developed de Dion-style rear axle conceived specifically for the EQG and chosen to provide “good traction and flexibility of the suspension”.
Each electric motor is able to provide individual drive to each wheel through a mechanical two-speed gearbox, offering both high and low-range gearing.
Together with traditional on-road driving modes (Eco, Comfort and Sport), the new G-Class will offer three off-road modes – Trail, Rock and Sand. An additional creeper mode allows the driver to set a pre-determined speed in off-road driving.
To facilitate off-road performance, the four electric motors are also able to simulate the three locking differentials (one in each axle, and one in the transfer case) of internal-combustion-engine G-Class models. In extreme conditions, the collective drive can be channelled to a single wheel to retain traction and ensure progress.
Schiller cites throttle dosing among the primary advantages of the four-motor layout. “It is incredibly precise. The individual control of drive to each wheel provides a whole new level of ability. We have even more possibilities off road. It is really fun every four weeks to drive the latest prototypes. I think we have the best electric off-roader,” he says.
Additionally, a so-called G-Turn function, activated by a dashboard-mounted button, makes the electric motors on one side turn the wheels forward and those on the opposite side turn the wheels in reverse, allowing the EQG to perform spectacular, on-the-spot 360deg tank turns. The driver can select whether to turn left or right via shift paddles on the steering wheel.
Compact packaging of the front electric motors within the front axle permits a greater turning angle for the front wheels, leading to a turning circle that is described as being “considerably better” than that of other internal-combustion-engine G-Class models.
The new driveline is allied to a battery mounted within the floor and beneath the rear seat. The lithium ion unit, with a usable energy capacity that Mercedes-Benz puts at "around 100kWh", shares its cell technology with that previewed by the EQXX concept. A new silicon anode is claimed to boost energy density and efficiency beyond that of the battery used by the newly unveiled EQE and EQS SUVs, while also providing a reduction in weight and overall size.
As in other Mercedes-Benz EQ models, a regeneration system allows the harvesting of kinetic energy in three different steps – D+, D and D-.
Schiller says it is too early in the development process to make claims about range, but he says the four electric motor layout provides the scope for significant energy regeneration, both in on-road and off-road driving.
“In off road, it is less about the overall range and more about driving hours. We’ve seen some incredible figures during testing,” he says.
To protect the battery in extreme off-road driving conditions, it is housed within a sturdy sealed case that enables the EQG to wade through deep water. The steel casing also receives an additional layer of carbonfibre-reinforced polymer compound to protect against rock strikes and other impacts.
“The outer layer is made of an extremely resilient material that is designed to protect the battery at all times,” says Schiller.
One advantage of mounting the battery within the floor is the EQG’s centre of gravity, which is described as being considerably lower than that of the G-Class. It comes at the cost of weight, though.
“Weight is a challenge – as it is in any electric vehicle,” says the head of Mercedes-Benz’s G-Class sub-brand, adding: “We haven’t got a final figure yet but it is below 3500kg.”
Underneath, a double-wishbone front and trailing arm rear suspension uses similar linkage points to internal-combustion-engine G-Class models.
Mercedes-Benz is not prepared to talk too much about factors such as ground clearance or approach, departure and break over angles just yet, though Schiller suggests the EQG will not only match diesel- and petrol-powered G-Class models in off-road conditions but, in certain situations, outperform them.
Despite the EQG’s ability to provide selective drive to each wheel, though, it appears prospective owners will have to forgo towing. “It is an absolute killer for the range, says Schiller. “We’re not sure at this stage if it will be offered on initial generation.
First ride: Mercedes-Benz EQG prototype
If Mercedes-Benz was at all concerned about the ability of the priceless EQG prototype its G-Class engineering team had brought to a secret testing ground near Toulouse in France, it wasn’t showing.
Straight from a technical presentation, we’re sat in the passenger seat and whisked into the throes of an early validation test for the new electric G-Class.
Rarely does a car maker allow us such early access to a new model. But here, just over a year after it was shown as a concept, we’re getting a first-hand look at what the EQG will be like when it goes on sale in 2024. Open gravel roads, where the new Mercedes-Benz makes light work of the conditions at higher speeds, soon give way to narrow trails strewn with redish-brown earth, loose rocks and, in more extreme sections, large exposed boulders.
We’re in the sort of territory that only a handful of series-production off-roaders are ever likely to venture, progressing at little more than walking pace up a 45deg incline in what Mercedes-Benz dubs creeper mode as the prototype’s four electric motors smoothly deliver drive to each individual wheel via a two-speed gearbox with low-range gearing.
There is no electrical whirring as the drive is sent to each wheel. Nor is there any electrical noise as the traction control system attempt to keep up. Merely the sound of rocks beneath the tyres and stones being sent against the inside of the wheelhouses - and with it a whole new sense of the surrounding nature.
The drivetrain refinement is more high-end limousine than extreme off-roader, giving the EQG a luxurious air from within.
Patience is required over many sections of our route. At some points, we balance precariously on three wheels, see-sawing off the ground. At others, the prototype crawls up steep rocky trails like a spider up a wall.
The ability of the EQG to continue on with commanding traction despite the treacherous conditions confirms it is already at a well-advanced state of development and, so it seems, every bit as capable as its diesel and petrol siblings away from the bitumen.
A new in-house-developed electronics system allows the electric motors to simulate the three locking differentials of other combustion-engine G-class models, enabling them to provide selective drive to the wheel with the most traction.
At one point, the CEO of the German car maker’s newly created G-Class sub-brand, Emmerich Schilling, delicately guides the EQG over a rocky crag. The drop is formidable. But such is the axle articulation and breadth of spring travel that we are somehow able to continue without pausing.
Before we reach the safety of the road below, though, there’s a significant rock strike against the underbody, which sends a shudder through the entire body. “It is in situations like these that we developed a new outer material for the battery casing. I would be worried right now if we just had a steel casing,” he says.
The off-road agility of the EQG is quite remarkable, aided by a smaller turning circle than that of existing G-Class models. The elevated seating, upright windscreen and sheer side glass, all elements of the G-Class since its inception in 1979, also provide outstanding visibility when the going gets rough.
Later, over wide and winding roads covered in sand, we reach speeds in excess of 80mph. Here, the EQG’s sophisticated air suspension does a superb job, absorbing bumps and undulations quickly and helping to minimise roll angles.
Near the end of the test, Schilling stops the EQG prototype in an open section of gravel, presses a button on the otherwise disguised dashboard and pulls on the left-hand side steering wheel paddle. “This is what we call the G-Turn,” he says as he plants the throttle and we are sent spinning on the spot. It is made possible by driving the electric motors on one side forward and those on the other side in reverse, allowing the electric G-Class to turn within its own length.
“At first we thought the G-Turn would be a nice feature to have but not entirely necessary. But after testing it, we discovered it does offer practical advantages in tight situations off road and decided to offer it on the production model,” he says. “It’s not the only surprise we have in store, though.”
Like all G-Class models down through the years, this new one has been developed to conquer the legendary Schoeckl. Before it is signed off for production, it will undergo a planned 300 runs up and down the demanding 3.4-mile trail close to the Magna-Steyr factory where the EQG will be produced in Graz, Austria.
There is still a lot about the EQG to discover some two years out from its planned launch. But even at this early stage, it is safe to say no other electric-powered off-roader delivers quite the same degree of rough road competence. The way it is able to traverse challenging terrain, climb steep grades and decend rocky trails is quite astonishing. It may be electric and weigh well over three tonnes, but for outright ability and agility away from the bitumen, it is a true G-Class - and, it must be said, really rather brilliant.