Mercedes-AMG surprised no one at this past November at the Los Angeles Auto Show when it took the wraps off the two most powerful SUVs AMG makes, the three-row GLS 63 and the two-row GLE 63 S, the latter being the subject of this review. The key specs: 603 horsepower, 627 lb-ft of torque, plus some sort of (I missed the press conference and never really got the full story) hybrid assist.
Fast-forward four months, and I find myself cruising west on the Pacific Coast Highway through Malibu behind the wheel of a blue GLE 63 S. I'm not going too much over speed limit, 70 mph or so, and there's a little blue square on the dashboard telling me the big boy is only using four of its eight cylinders. Moreover, another digital readout is letting me know that electric motor is sending power to the transmission. What sort of an AMG is this?
A complex one, it turns out. The GLE 63 S (and the mechanically identical GLS 63) is the first AMG to feature Mercedes' 48-volt V-8 engine, code-named M176. This 4.0-liter twin turbo engine replaces the old M157 5.5-liter twin-turbo V-8. The 48-volt V-8 is smaller, lighter, (maybe) more efficient, and most important for AMG, makes more power and torque. Like the M256 inline-six, the M176 is beltless and uses both an electronic water pump and AC compressor, and both the starter and the alternator are replaced by the integrated starter-generator, or ISG. In addition to starting the thing up and supplying juice to the various 48-volt systems, the ISG can also supply 21 horsepower and 184 lb-ft of torque.
Does that mean the GLE 63 S' total system output is 624 hp (603 + 21) and 811 lb-ft of torque (627 + 184)? No. That's not how it works. That 184 lb-ft occurs at zero rpm, before the ISG starts spinning. Peak torque for the V-8 happens at over 5,000 rpm, and by that point the ISG is contributing nothing. It's a black, technical art that I don't fully understand.
That said, AMG claims this SUV will hit 60 mph in 3.7 seconds. Weirdly, we never tested a previous-generation GLE 63, but we did clock a GLE 63 Coupe that hit 60 mph in 3.9 seconds. That makes 3.7 seconds sound totally feasible, though I have a hunch this beast will be even quicker. If I may make a prediction, I'd bet this puppy runs the quarter mile in 12.0 seconds, beating the GLE 63 S' 12.5-second time. Maybe even 11.9. Call it a hunch. If you take nothing else away from this review, know this: This machine feels absurdly quick and overly potent, and it will have you laughing every time you kick the throttle.
In addition to 48-volt engine accessories, the GLE 63 S comes with AMG's Active Ride Control, a 48-Volt active anti-roll bar that uses a set of planetary gears on each bar to counter act body movements. Put more quickly, this system keeps the GLE 63 S pretty much flat through corners. This sucker probably weighs 5,300 pounds, seeing as a 2020 GLE 450, a similar vehicle with the same air springs but with a six-cylinder engine, tipped the scales at 5,178 pounds. Notice I said air springs and not the fast-acting, hydraulic dampers that are available on the GLE 450. The ones that bounce. Why not? AMG claims that the hydraulic system is too heavy, a statement that's laughable on the surface until you realize that there's a 260-pound weight penalty between the air-sprung SUVs and the hydraulically sprung versions.
Sadly, this means that neither truck has the escape-from-sand/bounce mode of the car with hydraulic suspension. However, the air springs can raise the truck 2.1 inches. This thing and the GLS 63 are also the first AMG SUVs to feature active engine mounts. Curiously, the magnetic fluid-filled engine mounts work off of a secondary 12-volt system. Why is there a 12-volt system? For things like headlights and the stereo—systems that don't benefit from 48 volts. Charging magnetic particles suspended in fluid uses very little energy. Who knew?
But enough tech talk—how does the newest GLE 63 S drive? Like a boxing glove filled with lead shot. Switching the GLE 63 S out of Comfort mode and into something more brutal like Sport, Sport+, or Race wakes this thing right the hell up. The torque boost from the ISG effectively eliminates turbo lag (despite the M176's "hot inner V" configuration—both turbos sit inside the V-8's V for the shortest possible runners—there's lag), and it turns out 603 horsepower is a lot of power. Will you see 100 mph much more frequently than you might like should you bigfoot the GLE 63 S around? I know I did! AMG's claimed 3.7 seconds to 60 mph actually/suddenly sounds like a large underestimate.
Steering is what it is, but there's just no way to mask 2.5 tons. Grip, however, is incredible, as all four wheels are wrapped in massive Michelins. 285/40ZR22s up front, 325/35ZR22s rear. What's that mean? You can hustle the GLE 63 S as hard as you like on your favorite canyon road; it just feels a bit wooden. Look, AMG is fully capable of making great-handling cars, but they tend to be the ones the gang in Affalterbach engineers from (basically) the ground up, like the GT sports car and the four-door GT … sports car. In a sense, then, the GLE 63 S is a throwback to the old hammers from AMG. Way more power than you need, not too much else. I see no problem there.
Should you select the Individual mode, there's a way to tailor both the suspension's level of aggressiveness as well as the active anti-roll bars. AMG calls the later simply Dynamics, and your choices are Basic, Advanced, Pro, and Master. Personally, I like when vehicles lean into corners (not too much, just the right amount) and although I played with these custom settings, this GLE never felt great. To sum up sporty driving: way more capability than you'll likely ever need, and it just doesn't feel comfortable doing so. The brakes, I should point out, are stout.
One philosophical gripe if I may: When you're doing normal, around-town driving—a task that the GLE 63 S is nicely suited for—the SUV slips into V-4 mode fairly frequently. That's cool because why use all eight cylinders if you don't need them? Why not take advantage of the extra torque from the ISG to more cleanly propel the thing down the freeway? That's how AMG sees the world, and I was impressed by how often the GLE ran on just four cylinders. Even under light acceleration. However, every time cylinder deactivation happens, a blue icon lights up on the screen. I hate it. It's both distracting and ignoble. I would not be happy plunking down $114,945 (that's the base price when these go on sale this summer—the one I drove stickers at $133,075) and having to look at this blue square constantly popping up. Sure, you'd learn to ignore it, but then what's the point? The transition from eight to four pistons is pretty seamless, though if you know what to listen and look for, you can hear/feel a little judder when the fully-monty V-8 comes back to life. I imagine it's what running over a Prius feels like.
Taken as a whole, the Mercedes-AMG GLE 63 S is an impressive unit. More powerful than even AMG's mascot, the mighty G 63, this five-passenger SUV is a comfy, capable, pretty good-looking way to go drag racing. The GLE 63 S is missing the alacrity, the fleetness, the handling chops of the best of the crazy-powerful SUVs—think Lamborghini Urus, Alfa Romeo Stelvio Quadrifoglio, BMW X5M. The question then is, does it need it? I'd argue no, as I can't see the owners of a luxury tank like this ever going hunting for back roads. No, the GLE 63 S is a classic AMG. Power first, power foremost, and man that's some pretty sweet leather. Sports car fans should look elsewhere. AMG fans, you're home.
