Mercedes-AMG GLC63 S Coupe 2020 Specifications

Spawned from Mercedes-Benz's popular GLC-class compact luxury SUV lineup, the high-performance 2020 Mercedes-AMG GLC63 S coupe pegs the absurdity meter in nearly every metric. Take, for instance, its twin-turbocharged 4.0-liter V-8. Rated for 503 horsepower and 516 lb-ft of torque, it packs a 34-hp and 37-lb-ft advantage over the non-S GLC63, which makes do with just 469 horses and 479 lb-ft. Updated for 2020, like the not-at-all plebian Mercedes-Benz GLC300 on which it's based, the GLC63 S orbits in an entirely different solar system. Indeed, its V-8 doubles down on the GLC300's 255-hp 2.0-liter inline-four with twice the
cylinders, displacement, and turbos. The point, of course, is speed, and in that measurement, the GLC63 S coupe delivers as one of the quickest SUVs on the market.Proud to trade a bit of practicality for a rakish exterior, the GLC63 S coupe's 49 cubic feet of cargo capacity with its rear seats folded is eight cubes fewer than the more traditionally shaped GLC63 SUV's. It cedes only 1 cubic foot of room to its square-back sibling with its rear seats raised. This is true of all GLC coupes regardless of trim level, although Mercedes-AMG tells us that the GLC63 S SUV, which we have not had the chance to drive, will not be sold in the United States. This leaves the GLC63 S coupe as the only choice for Stateside customers determined to own the most potent GLC model available. We're sure Mercedes has its reasons for this decision, but it seems a bit of a missed opportunity considering that the new BMW X3 M and its fastback sibling, the X4 M, are offered in both standard and higher-powered Competition forms.As expected, forward thrust in the GLC63 S coupe still borders on the illogical, a trait we wholeheartedly endorse. There are no major mechanical changes versus last year's model. The standard nine-speed AMG-tuned automatic transmission, which employs a clutch pack in place of a conventional torque converter for heightened responses and weight savings, shuffles gears with typical German efficiency. Lifting off the GLC63's throttle at higher engine rpms produces plenty of pops and crackles from the V-8's exhaust. Although the tailpipe fireworks do seem a bit more restrained here than in some other AMG models we've driven, the deep, hearty bellow that the boosted V-8 emits is something we'll never tire of listening to. Dynamic engine mounts, which are exclusive to the GLC63 S, quell raucous engine vibrations that might find their way into the cabin.This latest 2020 model-year test vehicle wasn't quite as quick as the 2018 GLC63 S coupe we previously reviewed, perhaps due to production variances or perhaps the Michelin tires on the previous car help it to get out of the hole slightly better. Either way, the new model, tested in Michigan and weighing a negligible 38 pounds more than old car, stormed to 60 mph in 3.4 seconds and through the quarter-mile in 11.9 seconds at 114 mph—seriously quick, yet both of those measurements are 0.2 second off the pace of the previous, similar example tested in California. They also trial the quickest times we've recorded for the X3 M and X4 M, as well as the Alfa Romeo Stelvio Quadrifoglio. What's more, the 24.0 seconds that the latest GLC63 S coupe needed to reach 150 mph is more than two seconds longer than before.

Fuel economy likely isn't a primary concern for shoppers of fire-breathing SUVs, and that's for the best: we averaged just 14 mpg with the 2020 GLC63 S coupe and its return on our 75-mph highway fuel-economy test was only 20 mpg, or 2 mpg less than its EPA highway estimate.

For a vehicle with a relatively high center of gravity the GLC63 S is incredibly stable at speed. Credit the standard air-spring suspension and adaptive dampers for keeping things tight and reassuring; even on rougher sections of pavement the dampers react quickly to prevent harsh impacts from rattling the chassis without sacrificing overall body control. Based on our experiences with the previous GLC63 S, we were expecting a harsher ride across all of the selectable drive modes (Slippery, Comfort, Sport, Sport+, Individual, and Race) but found Sport to be nicely suited for all but the most broken pavement. Appropriate heft from the electrically assisted steering contributes to the AMG's secure feeling at higher speeds and direct responses when navigating twisty back roads. Standard 4matic+ all-wheel drive teams with a new-for-2020 electronically controlled limited-slip rear differential that aids corner-exit traction so much that AMG removed the previous brake-based torque-vectoring system. Unfortunately, the grip levels of our new test car at the track were lower than what we've previously recorded. Shod with 21-inch Pirelli P Zero summer tires—265/40ZR-21s in front and 295/35ZR-21s in back—the 2020 GLC63 S coupe circled the skidpad with 0.88 g of stick. Not only is that figure considerably less than the 0.94 g that the 2018 example managed on same-size Michelin Pilot Sport 4S rubber, but it's less grip than what some new family sedans on all-season tires can generate. The AMG's 159-foot stopping performance from 70 mph is similar to before, though.Technology continues to play a key role in extracting performance from the AMG's hardware. As before, the GLC63 S's various driving modes alter the behavior of its damping, steering, throttle, transmission, and exhaust settings. And for 2020 they are augmented by an additional four AMG Dynamics modes: Basic, Advanced, Pro, and Master. Bordering on overkill, they are paired to the drive settings and operate as subsystems that are capable of altering stability-control programming, engine-mount stiffness (in the S model), the rear-differential programming, and fore-aft torque distribution of the all-wheel-drive system. The Basic setting teams with Slippery and Comfort drive modes; Advanced pairs with Sport; Pro operates in Sport+ mode, and, in the S model only, Master mode kicks in when you deactivate the traction control in Sport+. Even finer adjustments of the AMG Dynamic settings are available via

console buttons and a steering wheel-mounted rotary control knob. If all this configurable minutia has your eyes glazing over, you're not alone. That said, we found the GLC63 S's core attributes to be so sufficiently dialed in that we found little need to fiddle with the various individual settings.

Thankfully, the focus on technology hasn't dampened Mercedes's enthusiasm for interior finery. From the helm, nothing you can see or touch would make you worry that other models in the segment are more luxurious. Benefitting from the same upgrades as the rest of the 2020 GLC lineup, the GLC63 S features a 12.3-inch digital instrument cluster, a 10.3-inch center display screen, an available assistant for the MBUX infotainment system, and the latest Mercedes steering wheel with mini touchpad controls. Standard sport seats do a good job of blending comfort and support without cramping backsides during long stints behind the wheel.

The 2020 Mercedes-AMG GLC63 S coupe sports a base price of $85,095—$7,600 more than the non-S GLC63 coupe and $10,350 more than the GLC63 SUV. With options, notably $2250 for AMG-badged 21-inch wheels (20s are standard), an $1100 head-up display, and a couple bundles of driver-assistance systems, the 2020 model we tested came to $96,425. But for fans of the absurd—and the absurdly good—the GLC63 S is impossible to ignore.

Specifications

2020 Mercedes-Benz GLC63 S Coupe 4Matic+

VEHICLE TYPEfront-engine, all-wheel drive, 5-passenger, 4-door hatchback

PRICE AS TESTED$96,425 (base price: $85,095)

ENGINE TYPEtwin-turbocharged and intercooled DOHC 32-valve V-8, aluminum block and heads, direct fuel injection
Displacement243 cu in, 3982
Power503 hp @ 6250 rpm
Torque516 lb-ft @ 1750 rpm

TRANSMISSION9-speed automatic

CHASSISSuspension (F/R): multilink/multilink
Brakes (F/R): 15.4-in vented, cross-drilled disc/14.2-in vented, cross-drilled grooved disc
Tires: Pirelli P Zero, F: 265/40ZR-21 (105Y) MO1 R: 295/35ZR-21 (107Y) MO1

DIMENSIONSWheelbase: 113.1 in
Length: 186.9 in
Width: 76.0 in
Height: 62.4 in
Cargo volume: 18 cu ft
Curb weight: 4555 lb

C/D
TEST RESULTSRollout, 1 ft: 0.3 sec
60 mph: 3.4 sec
100 mph: 8.8 sec
130 mph: 15.9 sec
150 mph: 24.0 sec
Rolling start, 5–60 mph: 4.6 sec
Top gear, 30–50 mph: 2.7 sec
Top gear, 50–70 mph: 3.0 sec
¼-mile: 11.9 sec @ 114 mph
Top speed (governor limited, mfr's claim): 174 mph
Braking, 70–0 mph: 159 ft
Roadholding, 300-ft-dia skidpad*: 0.88 g
*stability-control-inhibited

C/D
FUEL ECONOMYObserved: 14 mpg
75-mph highway driving: 20 mpg
Highway range: 340 miles

EPA FUEL ECONOMYCombined/city/highway: 18/16/22 mpg