The brain can't make sense of it. Watching it gums up the pattern recognition machine at the center of our gray matter. Years of experience and reinforcement have provided an accurate model of how a big, high-riding, comfy SUV will flop itself around a corner. At the wheel of the 2021 Bentley Bentayga, that prediction is always wrong. The calculus in your neurological filing cabinet won't add up when it comes to machines like this.
This is endemic to the whole fleet of modern super-SUVs. It goes beyond the supercar/sports sedan more-grip-than-you-can-comprehend phenomenon, because it's more than just an increase in capability. It is a fundamental shift in how vehicles handle their weight.
The culprit is the active anti-roll bar. It's the single element that allows the Lamborghini Urus, Aston Martin DBX, Porsche Cayenne Turbo, Bentley Bentayga, and Audi RS Q8 to corner flat and still ride well. A traditional anti-roll bar has a set stiffness; stiffer bars allow flatter cornering but also tie wheel motions together and amplify bumps. A softer setup will improve comfort, but won't be able to resist body roll.
With an active anti-roll bar, the resistance to roll is provided by an electric motor mounted between the wheels. This allows the car to vary resistance. In hard cornering, the electric motor uses all of its might to counteract body roll. Settle on a straight and you can reduce resistance, which in turn softens the impact of bumps and vibrations.
"In the case of the Bentayga, you can have an anti-roll system that is infinitely variable," Bentley head of product communications Mike Sayer told Road & Track. "So you can set the chassis to be extremely sporty with very, very stiff anti-roll bars, or you can turn the system off completely, which has the effect of deleting the anti-roll bars. Which, when you're off-road, means that every wheel can individually reach full droop. That's what you want for really good traction if you're bouncing around off-road."
These systems are not brand-new. Experimentation with active anti-roll bars started back in the Eighties. The big leap came with the advent of 48-volt electrical systems, which provide more electrical force for the motors to work with. That means faster reactions and higher maximum forces. According to Sayer, the Bentley Dynamic Ride Control system can go from zero torque to its maximum output of 962 lb-ft of torque in less than a third of a second. That's enough twist to entirely eliminate body roll in the huge Bentayga, but Bentley dialed the system back a bit, because driving with zero roll was unsettling.
There's even more adjustability in the system. By varying the relative stiffness of the front and rear axles, the system can adjust a car's balance as well as its behavior at the limit. When your big luxury SUV is in comfort mode, it's probably tuned toward understeer; dial in to sport mode for a canyon drive, and you'll want the on-throttle adjustability that comes with a bias toward oversteer.
This level of adjustability is no substitute for proper tuning. Getting the settings right is a daunting task made all the more complicated by the adjustability of countless other active systems. Between active anti-roll bars, air springs, adaptive dampers, four-wheel steering, torque-vectoring differentials, electric variable power steering, throttle-by-wire, brake-by-wire, all-wheel-drive torque splits, transmission programming, and more, a dizzying number of adjustments must be tuned and synchronized for each drive mode. Doing it well gives a vehicle an astounding amount of flexibility, creating ultra-comfortable tourers that corner like proper sports sedans.
But if any one of these systems goes out of step with the rest, it can sink the whole experience. Preventing that involves spending a ton of time and money on tuning. The final result, ideally, is a vehicle that's capable of things no vehicle with a conventional anti-roll-bar setup could ever accomplish.
Yet something still feels slightly unnatural. A Lamborghini Urus may corner with the same velocity and flatness as a BMW M5, but in the SUV, you can feel something digital going on between you and the road. You can’t consciously sense the fraction-of-a-second moments when the computerized anti-roll system is making changes, but a part of your brain never stops noticing some mysterious force helping you along. That dark magic can make it harder to build confidence in the machine, and in your ability to master it.
These are likely teething issues. The first 48-volt active anti-roll bar launched on the Bentayga in 2016. The technology spread rapidly among VW Group brands, then to certain outside players like the DBX. It's likely to expand to the entire auto industry with time. It's a monumental development, a bombshell that broke the dam and released a flood of super-SUVs capable of unhinged cornering speeds. Just don't be surprised if your brain can't quite keep up.
Arguably the most fickle member of the Road & Track staff, Reviews Editor Mack Hogan is likely the only person to ever cross shop an ND Miata with an Isuzu Vehicross. He founded the automotive reviews section of CNBC during his sophomore year of college and has been writing about cars ever since.
