AMG E Performance promises over 804 hp from potent plug-in hybrids

Mercedes-AMG is looking to electrification for the next big thing in performance, but it's not quite ready to give up on gas engines yet. The result is AMG E Performance, a new family of horsepower-heavy hybrids that combine gas and electric for all-wheel drive with some fascinating nuance.

AMG is no stranger to electrification, of course. Mercedes' in-house tuner offers several hybrids using the EQ Boost system, which adds an electric starter-generator to the gas drivetrain that helps with short periods of extra grunt. EQ Boost, though, relies on regenerative energy alone: you can't plug the car in to charge the battery, and it's not designed to move the hybrid solely on electric power.

AMG E Performance goes much further. For a start it's based around the idea of a true plug-in hybrid, with a larger battery that will support some EV-only driving. AMG, though, isn't really focusing on that as a use case: instead, it wants to use the electric part of the system to increase performance.

Effectively, there'll be a gas engine and its transmission up at the front, driving the front wheels, and an electric drive unit at the rear, driving the rear wheels. The result will be hybrid all-wheel drive, or e-AWD. AMG will have two versions to begin with, one with a 4.0-liter V8 biturbo gas engine and the other with a 2.0-liter inline-four turbo.

There are a fair few differences here to what we've seen from other performance hybrids. For a start, both gas and electric parts of the system have their own gearboxes. At the front, for the gas engine, there's a 9-speed AMG Speedshift MCT; the rear gets a 2-speed transmission for the electric motor.

That's an odd setup, generally, but AMG insists it delivers the best of performance and efficiency. Without routing power via the 9-speed, for example, the electric motor more effectively puts it down to the rear axle. Since it can spin up to 13,500 rpm, the 2-speed electric motor gearbox means it can be used across the full range of the gas engine, too. That shift happens automatically at about 87 mph.

An integrated, electronically-controlled rear axle differential lock can push torque from left to right on the rear axle. However thanks to the drive shaft running from front to rear, and the shafts of the front wheels, electric motor torque can also be pushed to the front to maximize performance or overcome slip.

The battery, meanwhile, isn't located under the cabin as in most EVs, but on the rear axle with the electric motor and other components. AMG says that ensures the best possible weight distribution. It uses an in-house Li-Ion design, with 560 cells that promise twice the power density of a traditional battery. The high energy throughput means more efficient charge and discharge, which is vital when you're trying to maximize getting juice out to the electric motor, or make the most of recuperated power to top the battery back up.

AMG says it's capable of pushing out 70 kW of continuous power, or 150 kW of peak power. On the flip side, it can handle up to 90 kW getting pushed back into the battery. There's direct fluid cooling to make sure the whole thing doesn't overheat: about 3.7 gallons of non-conductive liquid that cycles around to keep things at 113 degrees Fahrenheit.

The outcome is the HPB80 battery with 6.1 kWh capacity, 94 hp of continuous power, and 201 hp of peak power for up to 10 seconds, all wight a weight of 196 pounds. It's designed to be scalable, too, so future implementations – or different sizes of vehicle – could be bigger or smaller on the same principles.

The grand result is some seriously impressive power figures. With the V8 engine, for instance, AMG says we can expect more than 804 horsepower in total, and over 738 lb-ft of system torque. Obviously the individual vehicle itself will make a different to overall performance, but sub-3.0 second 0-60 mph times are certainly possible, AMG claims.

The four-cylinder Performance Hybrid, meanwhile, may be down on displacement but the overall package is still a potent one. An electric exhaust-gas turbocharger helps the gas engine alone deliver over 442 horsepower, with the electric motor contributing up to 201 horsepower. The result, AMG says, is more power than current non-hybrid V8 cars.

Either way, there'll be four levels of driver-selectable regeneration. Level 0 will feel much like a manual transmission car with the clutch depressed, with minimal rolling resistance when you lift off the accelerator. Level 1 – which will be the default – will feel like a regular gas engine in deceleration. Level 2 will factor in stronger recuperation, with a driver only rarely needing to use the brake pedal; finally, Level 3 will be for one-pedal driving.

Which is selected will also depend on which AMG DYNAMIC SELECT and AMG DYNAMICS drive mode is active. For the former, there'll be Electric, Comfort, Sport, Sport+, Race, and Individual, each adjusting factors like steering, drivetrain responsiveness, chassis damping, and sound. It'll run the gamut from near-silent operation, through all-electric driving at up to 81 mph, to using both power sources for maximum speed.

At the same time there'll also be AMG DYNAMICS which adjusts things like the rear differential lock, the e-AWD, and the ESP. That'll have Basic, Advanced, Pro, and Master modes, with various different levels of electronic assistance, stability control, and more.

As you might expect, all this extra hardware does introduce some more weight. There's around 440 pounds more from the battery, charger, electric motor, and other components, but AMG insists that not only does that help with weight balance, but the amount of power added is far greater than the added weight.

Something you don't get, though, is DC fast charging. That would've added more weight still, and AMG decided to draw a line there. On a race track, it points out, the warm-up lap alone would probably be sufficient to charge the battery with enough power to use on the second lap.

We'll see the V8 version of the AMG E Performance system appear first in the upcoming AMG GT four-door coupe. The four-cylinder version, meanwhile, will make its debut in the upcoming AMG C-Class, which the automaker promises "will set standards in terms of power density" and be as aggressively potent as the current C63. Expect more details on those cars later in 2021, along with the reveal of the all-electric AMG EQ line-up.