In the rarefied air of posh three-row SUVs, the Mercedes-Benz GLS stands out as a top player, offering loads of performance, comfort, and opulence for the money. But convoluted controls hurt its road-test score, and below-average predicted reliability drags down its Overall Score.
The GLS is essentially an elongated version of the midsized GLE SUV with an incredibly roomy cabin and a relatively roomy third-row seat that’s actually usable for teens and adults. Front- and middle-row seats also provide first-class comfort, and the cabin is wrapped in top-notch leather, chrome, and wood.
The ride is very comfortable and steady thanks to the standard air suspension system, which helps keep passengers blissfully unaware of most road imperfections.
Handling feels secure and there’s little body lean when taking corners. Although there’s no hiding this SUV's bulk, the steering responds promptly to inputs., contributing to making the massive GLS feel slightly smaller than it really is.
The GLS450’s turbocharged six-cylinder engine and nine-speed automatic transmission combine to deliver effortless power without any hesitation. The engine is coupled to a 48-volt mild hybrid setup that allows accessories to operate without taxing the engine, and makes the stop/start function work smoothly, too. As such, the powertrain is fantastic, accelerating this 5,500-pound luxury coach with urgency, while achieving 20 mpg overall.
The seats are top notch to begin with—but with the optional massage feature, they become truly pampering. Moreover, we highly recommend selecting the Warmth and Comfort package, which includes heated armrests, including those on the doors for front passengers—they're great on a chilly morning.
Even six-foot tall passengers will find the second-row seats roomy, and the cabin feels quite airy thanks to big windows and standard panoramic sunroof. But the controls could be a deal-breaker. They are distracting to use and take a good deal of time to master. Many functions are buried in a digital version of a customer-service phone tree. Some actions take several steps, such as adjusting the seat’s lumbar support—that’s ridiculous. It’s easy to inadvertently brush any of the car's many touch-based controllers and end up changing a display or audio selection, or toggle to a different setting entirely.
This big Benz comes standard with forward collision warning (FCW), automatic emergency braking (AEB) with pedestrian detection, and blind spot warning (BSW). The optional driving assistance package includes adaptive cruise control and lane centering that is even capable of switching lanes upon the driver signaling. We found it a convenience.