Mercedes-Benz is introducing the AMG high-performance versions of its big-selling GLC SUV. The news is both good (up to 680hp!) and bad (no more gurgling V8 engine...).
The new GLC AMG models will share a common turbocharged four-cylinder petrol engine. The GLC 43 AMG gives you 421hp and 500Nm of torque, with a boost of up to 14hp from the 48-volt mild-hybrid starter/generator. It's enough to shove the GLC 43 AMG to 100km/h from rest in just 4.8 seconds. The top speed is limited to 250km/h.
AMG plug-in hybrid
Want more? You can have more. The GLC 63 AMG S E-Performance version is a plug-in hybrid and shares its powertrain with the high-performance C 63 AMG C-Class. In this setup, the 2.0-litre turbo engine - the same 'M139' unit as in the GLC 43 AMG - stretches to a whopping 476hp. But it's not working alone - this time, there's a 204hp electric motor, fed power from a rechargeable 6.1kWh battery pack, which ramps up the total power to 680hp. The combined torque available from both power sources is a colossal 1,020Nm. That's enough to trim the 0-100km/h time to a ridiculous 4.5 seconds. The 63 gets a top speed of 275km/h.
How has Mercedes gotten that much oomph out of a four-cylinder mild-hybrid? Well, it helps that AMG can lean on the expertise of Merc's Formula One team, which has helped in the design of the engine's electric and exhaust-driven turbo. An electric motor around 4cm thin is integrated directly on the turbocharger shaft between the turbine wheel on the exhaust side and the compressor wheel on the intake side. This directly drives the shaft of the turbocharger and is electronically controlled, accelerating the compressor wheel to a crazy 175,000rpm before the exhaust gas flow takes over the drive conventionally.
What does that mean? Sharper response. More low-down torque. Grunt. While the two engine versions share a common structure and layout, the 63 version's turbo is considerably larger than the 43's, giving it that massive performance boost. Both engine versions also get two-stage direct fuel injection, which gives sharper response to throttle inputs.
An extra gearbox
The 63 also gets a special transmission, in which the rear-mounted electric motor has its own two-speed gearbox to make for snappier reactions at low speeds. Being as the GLC is, of course, four-wheel drive, if the system detects any slip at the rear wheels (which seems pretty likely, with all that torque), it can direct power to the front wheels to stabilise the car.
The plug-in hybrid battery has also benefited from Merc's F1 experience and is capable of continuous power output of 150kW to help the GLC 63 maintain peak performance for as long as possible. You can recharge the battery from a 3.7kW charging source (a home three-pin socket will do nicely), giving you a maximum range of 12km on a full charge. Not massive, but potentially useful at least.
To keep the battery in good nick, there's a full cooling circuit, which flows non-conductive cooling liquid around each of the battery cells to try and keep it as close to its optimum 45-degree operating temperature as possible. That cooling, and the 150kW output, also means that the car's highest performance potential is available at any moment as soon as you push the accelerator pedal into kick down.
The mounting of the electric motor close to the rear axle also means that the GLC 63 has, effectively, two stability and traction control systems, as the electric motor can be adjusted more quickly than the combustion motor. Mercedes says that, in some circumstances, the necessary stability control inputs can be made just by tweaking the electric motor without needing to bring in the petrol engine's control systems.
Both cars use a nine-speed 'MCT-9G' dual-clutch gearbox with a wet clutch instead of a torque convertor, which helps reduce weight and speed up shift times. The two cars do get different power splits, though. The GLC 43 AMG sends 69 per cent of its power to the rear axle, with 31 per cent going to the front. The GLC 63 AMG sends 50 per cent to both ends most of the time but can shunt 100 per cent to the rear wheels when needed.
As you'd expect, there is a full suite of adjustable driving modes and setups, with five selectable modes for the GLC 43 and eight for the GLC 63. Both cars get adaptive electronically-controlled suspension dampers and active anti-roll for the GLC 63. There's also a specially-tweaked AMG steering setup and rear-wheel steering, making the GLC more manoeuvrable in town.
Sports exhaust
While the old V8 engine's music may be absent, these four-cylinder engines should still make plenty of noise, thanks to a sports exhaust system. Braking is taken care of by internally ventilated and perforated brake discs measuring 370 x 36 millimetres. with four-piston fixed callipers fitted to the front axle and 360 x 26 millimetres with one-piston floating callipers at the rear for the GLC 43, while the GLC 63 gets six-piston fixed callipers at the front (internally ventilated and perforated brake discs measuring 390 x 36mm) and one-piston floating callipers at the rear (internally ventilated and perforated brake discs 370 x 26mm).
On the outside, both cars get the AMG 'Panamericana' radiator grille and a distinctive AMG body kit featuring aero flicks, large intakes and air curtains. Inside, you'll find an AMG Performance steering wheel and specific AMG displays for the big dashboard screens. Also integrated is AMG Track Pace (standard in the GLC 63 S, optional for the GLC 43), the data logger for use on the racetrack. The software records over 80 vehicle-specific data such as speed, acceleration and steering angle ten times per second while driving around a race track.
"The Mercedes-AMG GLC SUV is an absolute success with our customers. Our two versions with different characters for the sporty-urban lifestyle are superior all-rounders and precisely tailored to individual customer wishes. With the E-Performance drive in the GLC 63 S, we are also launching the first performance hybrid SUV. The all-wheel-drive system, the active rear-axle steering and the quick-shifting transmission enhance the emotionally appealing hallmark AMG driving experience," said Michael Schiebe, CEO of Mercedes-AMG.