Mercedes-Benz EQC 4×4²: the Terminator-like electric off-roader

The Mercedes-Benz EQC 4×4² rides on special axles that let it clamber over almost anything in its path - a kind of Terminator shaped like an SUV.

Electromobility is often about eking out a few extra miles of range from the same battery charge, which encourages a very measured driving style. Right? Well… not always. The Mercedes-Benz EQC 4×4² concept throws that idea out of the window: with huge wheels mounted on portal axles, it takes on the look of a ravenous monster that devours defenceless Smarts for breakfast.

“‘We call it EQnator’ (from EQC + Terminator),” jokes Hendrik Loos, one of the engineers in the small development team. He doesn’t rule out this cyborg-like 4×4 being requested by a film producer to star in a hypothetical new instalment (in that case, the seventh) of the famous movie saga, after the most recent chapter at the end of 2019.

Unstoppable EQC 4×4²!

Built to demonstrate the potential of electric 4×4 vehicles, this prototype starts with the EQC 400 4Matic - but looks as though it has been put on an anabolic steroid regime to inflate its “lower limbs”. The trick lies in the portal axles, where the main axle sits above the wheel centre and, at the axle end (where it meets the wheel), there is a gearbox.

Because the axle and differential housing sit higher up, ground clearance increases dramatically - here to 29.3 cm. That is more than double what you get in a standard EQC, and also 5.8 cm more than a Mercedes-Benz G-Class, for instance, which many regard as an all-terrain icon.

And when you compare its off-road figures with those of a regular EQC, the differences are striking: approach and departure angles rise from 20° to more than 30°, the breakover angle more than doubles (from 11.6° to 24.2°), and wading depth jumps to 400 mm instead of 250 mm - again putting it ahead of the G-Class in those very same abilities.

An EQC up on tiptoes

What might look straightforward actually demanded plenty of ingenuity. From the outset, the team knew portal axles would be used, which meant positioning the axle much higher where it connects to the wheel. Mercedes could even have drawn on the axles used to turn the G-Class into the G500 4×4² - another member of the family. This EQC 4×4² is the third member, with the E-Class All-Terrain as the second - revealed at the start of 2016 and even built in a small production run.

The snag was that the G500 axle would not fit under the EQC. The answer was to adopt the chassis from the E-Class All-Terrain 4×4 and modify it for the EQC, widening the wheel arches by 10 cm on each side - also so the 20-inch wheels could be accommodated.

As project lead Juergen Ebeler explains, “this transplant forced us to come up with some quite elaborate solutions, such as installing an electric motor in place of the differential on the rear axle. That also required a different subframe and suspension wishbones so the original air suspension, with slightly firmer tuning, could fit.” Up front, the changes were more modest, going little beyond revising the axle kinematics.

Off-road drive modes and calibration

The Offroad driving programmes are the same as on the GLC, but two more have been added (making seven in total). One is intended for t-r-u-l-y demanding terrain and is called Offroad Plus, although the modes have been recalibrated to deliver higher torque on pull-away over loose surfaces. The new Offroad mode also brings a new throttle map for situations where you need to manage the SUV’s progress “with tweezers”, sometimes at speeds slower than a person’s walking pace.

Powertrain, battery and protection

The propulsion system is the familiar one: two electric motors (one per axle) producing 204 hp and 380 Nm each, for a combined output of 408 hp and 760 Nm. They are fed by the same battery, positioned in the floor between the axles, with 80 kWh of usable capacity.

That hefty energy store actually helps make this off-roader capable on genuinely tough trails - not only because the battery lowers the centre of gravity, but also because the protection around it means you can do without the extra shields for the engine and gearbox that are common on this kind of vehicle. The absence of a bulky engine/gearbox assembly also contributes to a smaller turning circle.

Another curiosity of the EQC 4×4² is that it can sound as menacing as it looks. Inside the space allocated to the front headlamps sit speakers that generate the sound that best expresses the vehicle’s movement, depending on the selected driving mode and parameters such as accelerator position, vehicle speed and the energy recuperation rate. The sound is also piped into the cabin of this Mercedes-Benz that aims to conquer the world without limits - hence the roof tent and even a small inflatable dinghy so the journey can continue even when there is no more reasonably firm ground ahead.

To infinity and beyond? Yes and no…

With all that equipment, you might say the main barrier to setting off on a globe-conquering adventure is range. The quoted 414 km for a standard EQC may not stretch to much more than half that if off-road driving is particularly demanding. In other words, it’s fine - as long as the end of the world is… close to home.

This time behind the wheel of the “beast” took place in a quarry packed with “traps”: from sharp rocks to deep craters, plus piles of sand like dunes. The EQC 4×4² left almost all of it behind without so much as “messing up its hair”.

It is true there is no low-range gearbox, but with 760 Nm of “instant” torque (because… electric), huge axle articulation, and those generous off-road angles and ground clearance, a transfer case was not missed at all. There are no locking differentials either (as you would find on a G-Class, for example), but brake-based stability control does the job.

You could argue it was harder to climb up into the driving position of this EQC 4×4² - around 20 cm higher - than it was to overcome the obstacles the terrain presented. The dashboard is identical in every respect to that of a “normal” EQC, unlike the first impressions on the move: both the greater ride height and the remarkable silence of electric propulsion feel even more dramatic in this “war zone” setting than they do in an EV driven on tarmac. The clearly audible effort an engine normally makes when “unsticking” an off-roader from tougher obstacles is absent here, replaced by calming quiet… and by the sound of stones thudding against the SUV’s underside or sand being shredded by the 20-inch wheels.

Mercedes-Benz has no plans to build this mutant-looking EQC 4×4² as a series-production model, but the newly announced G sub-brand could benefit from several of the components developed by the small team of engineers who used their free time to create this project.

Among them is the all-electric G-Class, which is set to be one of the most anticipated models for the sizeable ranks of fans of the iconic square-cut 4×4. And, in the not-too-distant future, it will take on another off-road icon on wheels: the equally angular electric Hummer due to reach the market in 2021. A genuine Terminators-style showdown in prospect…

Authors: Joaquim Oliveira/Press-Inform.