From an electrically spun turbocharger, to rear axle steering, the GLC 43 and GLC 63 S E Performance bring mega capability to the crossover SUV space.

The 2024 Mercedes-AMG GLC 43 and GLC 63 (now called 63 S E Performance) return to the compact crossover line-up, but as hybrids. And with almost unbelievable levels of power. Under the hood of both lies a turbocharged 2.0-liter four-cylinder engine—mounted longitudinally. You also get a nine-speed automatic transmission.

Mercedes also added standard rear-axle steering, adaptive shock absorbers (named AMG Ride Control), active-roll stabilization (for the 63 S E Performance), and 4MATIC all-wheel-drive. But we need to talk more about this turbo-four.

Dubbed the M139L, Stuttgart’s latest engine takes horsepower-per-liter to the stratosphere. In the AMG 43, you get 416 horsepower and 369 lb.-ft of torque. That’s 208 HP/Liter, from a two-liter four-banger—from the factory. Aside from building an inherently strong engine to handle massive cylinder pressures, Mercedes incorporates clever technology, like an electrically assisted turbocharger.

A 1.6-inch thick electric motor mounts right on to the turbocharger shaft and spins the turbine up before the exhaust gas has enough energy to take over and spin up to 175,000 rpm. This setup allows the turbocharger to contribute flowing air into the cylinders faster and at a lower rpm, compared to traditional compressors. For the GLC 43, a 48-volt system supplies the needed juice.

To keep up with all the extra air, AMG pumps in the necessary fuel with a two-stage, dual-mode injection system. To start, Mercedes mounted piezo injectors directly into the combustion chamber to spit fuel at up to 2900 psi. But more fuel is added in the intake manifold with solenoid-valves to provide both port and direct injection.

Bolstering all of that, you also get a 13 horsepower bump at low revs from a belt-driven starter-generator motor, itself supplied power by the same 48-volt system used by the turbo. While not contributing to peak outputs, it adds even more flexibility to the already impressive M139L.

Rounding it all out is a nine-speed automatic transmission with a wet-clutch pack replacing the torque converter and a rear-biased 4MATIC all-wheel-drive system. Mercedes says the GLC needs but 4.7-seconds to 60 mph from rest and will happily cruise along at an electronically limited 155 mph.

And that’s the opening act. The 63 S E Performance combines a full-hybrid setup to deliver a jaw dropping 671 horsepower and 752 lb.-ft of torque! In 63 S guise, the turbocharged 2.0-liter ups peak power to 469 HP and 402 lb.-ft. Mercedes achieved this by using a bigger turbocharger and a 400-volt hybrid system to power it.

A rear axle mounted electric motor adds to the fun, providing a peak 201 horsepower. It get its electricity from a 6.1-kWh battery pack. This battery pack, by the way, can be charged by braking recuperation and an external source, making the GLC a plug-in-hybrid. But Mercedes did not offer many details about charging time and the rest.

Now, both the turbocharger and battery pack make use of technology first found in Formula 1. But the battery pack stems from direct communication between Mercedes F1 High Performance Powertrains in Brixworth UK and AMG in Affalterbach Germany.

Just as in Formula 1, the lithium-ion pack very quickly charges and depletes its stored energy, allowing for a very quick burst of power when needed. Made from 560 individual cells, a big part of their performance comes from a non-conductive special coolant that flows between each individual cell, and maintains a very precise operating temperature, which averages 113 degrees Fahrenheit.

Just like the GLC 43, you get a nine-speed automatic and 4MATIC drivetrain. But unlike the GLC, which is fixed to provide 31 percent of power to the front axle, 69 percent to the rear, the GLC 63 can vary between a 50/50 split and up to 100 percent to the rear axle. A rear-wheel-drive 671 horsepower compact SUV. Yes!

Standard rear-axle steering will turn up to 2.5 degrees in the opposite direction as the front axle when speeds are at or below 62 mph. Above that, the rear-axle will turn up to 0.7 degrees in the same direction. While the additional stability added during high-speed cornering is nice, I bet the main benefit for handling is from the additional low speed agility.

Speaking of, the GLC 63’s active roll stabilization is a clever system to add. Instead of single piece anti-roll bars, Mercedes mounts two separate bars on either side and connects them in the center with a planetary gear and actuator. On rough surfaces, the system essentially disconnects the bars, allowing fully independent articulation at each corner. Yet, in sport driving modes and with high lateral-g, the system not only connects the two bars, but also twists them to increase their resistance to body roll.

All this for a compact SUV. And while Mercedes-Benz didn’t share pricing yet, the base GLC300 starts at 50K, these will be a lot more than that. Then again, so is the performance. The outputs managed from the M139L blows my mind. And may, indeed, blow the doors off the GLC too. The only way to find out is a test drive. I CANNOT wait to review these as soon as they become available. And will excitedly share the moment I do.

Want to go full electric with your next SUV? The Polestar 3 will arrive soon.