Andrew Wendler • Self-help gurus have made an industry out of reminding humans they can’t be everything to everyone, but the message is lost on the manufacturers of SUVs and crossovers. As the market continues to tilt in favor of these vehicles, automakers remain engaged in a relentless battle to tame them for civilian duty while maintaining a degree of off-road ability.
Mercedes-Benz has long led the charge to skillfully blend these attributes (note the arrival of an independent front suspension in the redesigned G-wagen), and the car maker was so eager to share its latest developments that it invited us to Barber Motorsports Park for a ride-along in a prototype of the upcoming next-generation 2019 GLE SUV.
EDITOR'S NOTE: You're reading a story by American title Car and Driver. We're bringing you a handful of C/D stories each month, focused on vehicles we've either not yet driven, or models not offered in Australia. Where appropriate, we'll add metric measurements for reference, but grammar and terminology will otherwise remain unchanged.
Brains and Brawn
While the usual path to off-road supremacy involves lifting suspensions and locking differentials, that’s not practical for most mainstream applications. Mercedes believes that delivering the capability implied by the SUV moniker is still crucial to its integrity. To that end, the 2019 GLE450 takes a different tack, including utilizing a new-to-the-GLE air-spring suspension that offers a versatile set of driving parameters as well as a few out-of-character and, frankly, insane party tricks.
The driveline is composed of a nine-speed automatic transmission mated to a variable center differential, which directs torque forward as needed. Teamed with brake-based torque vectoring on both axles, this setup focuses on providing cool and confident traction by using brains over brawn. The engine is the turbocharged 3.0-liter M256 inline-six, which is paired with an integrated starter/generator and makes 362 horsepower (243kW) and 369 lb-ft of torque (500Nm).
The suspension utilizes an air spring at each corner, which not only replaces the steel coil springs but also eliminates the front and rear anti-roll bars. (Models without the off-road suspension package will retain steel springs and be fitted with anti-roll bars.) Inspired by the Magic Body Control system introduced on the 2012 S-Class, the air-spring setup features numerous properties intended to improve the GLE450’s off-road chops.
Moments after entering an off-road course carved from a hillside at the 880-acre Barber facility, one quality became apparent: Wheel hop and spin are virtually absent. Whether ascending an incline as steep as 54 degrees or performing tight turns in off-camber situations with the vehicle tilted at armrest-gripping angles, there was zero kickback at the steering wheel and virtually no slip of the Pirelli Scorpion ATR tires (size 275/50R-20).
Our driver for this section, Mercedes-Benz engineer and GLE testing lead Rüdiger Rutz, demonstrated the advantages of a system that can instantaneously adjust to the conditions at hand by repeatedly making full-lock turns.
“It drives with the traction of a system with front, rear, and center lockers, but we are still able to make tight turns without kickback,” he said. “To me it is like a cat.”
Several driving modes similar to those of current Mercedes-Benz products are offered, as is a low range; we spent the majority of our time off-road in, yes, Off-Road mode. Rutz only selected low range once or twice, and even then more just to show it was there than in a hunt for extra grunt.
A quick run through the photo gallery should provide a good idea of what we were up against.
Bagged and Dog-Legged
The traction systems are abetted by the air-spring suspension, which can provide approximately 11 inches (279mm) of maximum ground clearance. On only two occasions did the GLE’s nether regions make significant contact with the rocky terrain, and in both instances the hits were absorbed by the factory skid plates that come with the off-road suspension package.
In addition to the preset driving modes, a “Free Mode” allows the driver to raise or lower a wheel individually, to the point of hanging loose in the dog-leg style popularized by low-riders. While it is undecided if production models will offer the option of “lifting a leg,” it does demonstrate the fully integrated and well-balanced nature of the off-road air-spring suspension.
Equally as fascinating is a mode that automatically bounces the vehicle to help free it when stuck in deep sand. Owners may be inspired to affix an “If this GLE is rockin’...” bumper sticker.
We grabbed the shotgun seat in another GLE450, this one shod with a set of massive, 315-section Pirelli P Zeros wrapping 21-inch wheels. Despite the larger wheels and lower-profile rubber, the ride remained compliant with virtually no harsh impacts transmitted to the passenger compartment. By constantly adjusting their firmness based on a number of parameters—including information supplied by the Road Surface Scan camera, a bit of tech shared with the system in the S-Class – the air springs manage to deliver a real-time adaptability not available with steel springs.
The real trick here is the way the car mitigates roll control by firming or softening individual air bladders to alter body roll, and it goes without conventional anti-roll bars, active or otherwise.
Ripping around a small autocross-style circuit revealed firmly controlled body motions and an all-wheel-drive system biased slightly to the rear to allow for tight maneuvering, with a smidge of controllable rotation. The front springs firm up at high speeds for increased stability. We didn’t experience excessive sway or panic-inducing levels of lean at any speed.
The quickness and finesse with which the GLE navigated the autocross section once again verified how effective pneumatic springs—with their growing ability to make quick and precise proactive adjustments—can be. Rutz confided that while “the [Land Rover Range] Rover system is not bad, you still feel the weight and push of the vehicle in aggressive on-road directional changes. Not so here.”
Interestingly, the system permits the user to preselect among three levels of body lean to fit circumstances or personal preference. These were tangibly demonstrated during the on-road ride-along as the driver cycled through them to alternate between the first setting, which provides nearly flat cornering, and the more lenient third setting that actually tilts the body into the direction of the turn; this is an odd sensation at first, but with additional exposure it feels more natural. Particularly noticeable on long sweeping corners taken at speed, its effect was made more evident in a lead-and-follow session where it was easily visible from the following vehicle.
When asked if the off-road suspension would find its way into the rest of the Mercedes-Benz SUV lineup, Rutz replied, “definitely” but would not comment on the timeline.
As for further details regarding the new 2019 GLE, the only specific information we could extract from the engineers is that the wheelbase is about three inches (76mm) longer than the outgoing model; our eyes told us it doesn’t appear much larger overall.
Although we’ve barely begun to unwrap it, our short time with the 2019 Mercedes-Benz GLE indicates that while being everything to everyone might be an impossible task, its maker isn’t going to stop trying to achieve it anytime soon.