Gas-only AMG powertrains are dead, but their hybrid successors will still be gnarly
Even performance brands known for their world-beating engines aren’t immune to the impending electric tidal wave. Mercedes-AMG has revealed a host of details about its electrification strategy for its next generation of performance-minded cars, giving us a glimpse at how one of the industry’s most vaunted in-house speed shops intends to harness electrification in service of going faster. The tl;dr version reads like this: Gasoline-only AMGs are no more, as the same is true for that silky smooth straight-six with the integrated starter/generator unit found in the current E53 AMG coupe and sedan. With that Band-Aid ripped off, let’s dive in.
AMG envisions its electric strategy consisting of two pillars. The first is what it is calling E Performance, a new badge adorning AMG models that denotes plug-in hybridized drivetrains employing both traditional internal combustion engines as well as new electric motor and high-performance battery technology (more on that in a bit). The second pillar is a portfolio of all-electric battery-only AMG models, based on the Mercedes-Benz EQ platform.
Pillar one: E Performance hybrid vehicles
Put on your engineer hat, this gets a bit technical. The E Performance formula goes something like this: Take a gas engine up front—either AMG’s M177 4.0-liter twin-turbo V-8 or the M139 turbocharged four-cylinder—and add a synchronous electric motor with an electronically-shifted two-speed transmission onto the rear axle, as well as an ultra-high-performance battery derived from Formula 1 technology.
That new rear unit is the big deal here. AMG calls it an Electric Drive Unit (EDU) and it comprises an electric motor integrated with an electronically-shifted two-speed transmission and an electronically-controlled limited-slip rear diff. This compact EDU provides a host of benefits, from the instantaneous torque of electric motors, to torque vectoring on the rear axle for better corner-exit behavior, to enhanced weight distribution front-to-back. Depending on the model series, the EDU can provide up to 201 hp and 236 lb-ft of torque for short bursts—think electronic-push-to-pass in racing. The EDU also allows for completely electric driving at speeds of up to 81 mph if you’re in the correct drive mode, creatively named “Electric.”
In normal driving circumstances this EDU supplements the power that the ICE and the nine-speed automatic transmission are already sending to the rear wheels via AMG’s 4MATIC+ all-wheel-drive system. However, if the driver switches the six-mode AMG Dynamic Select system to Electric, it will utilize the EDU alone to motivate the car. But even then, if the computers detect rear wheel slip, the 4MATIC+ system will send some of that electric twist to the front wheels via the clutch-controlled transfer case while the nine-speed transmission decouples the carbon-producing engine.
Of course, the juice for that high-tech motor has to come from somewhere. Just above the EDU at the rear of the car sits the new AMG High Performance Battery (HPB). This 6.1-kWh lithium-ion battery traces its roots to the Mercedes-AMG Petronas Formula 1 team. Thanks to advancements like individual battery cell cooling, the battery offers 94 horsepower of continuous juice and up to 201 ponies in short 10-second bursts. It weighs just 196 pounds, achieving that 1.0 hp/pound density, which is around twice the density of conventional drive batteries. Impressively, this hybridized drivetrain will offer one-pedal driving in certain traffic situations, thanks to a four-stage selectable recuperation system. Level 0 is almost no noticeable recuperation, while level 3 offers the highest energy recovery—up to 90 kW.
That’s a lot to wade through, but the net results are staggering: Peak total system output between the new HPB and the conventional gas-burning engine is “over 804 horsepower and more than 738 lb-ft,” according to Mercedes. Depending on the vehicle that the drivetrain is motivating, that will mean 0–60 times below 3 seconds.
The M139 four-cylinder engine is also undergoing a host of upgrades for these new E Performance cars. In the current AMG applications, the four-banger is mounted transversely; in the future E Performance variants, it will be mounted longitudinally. Additionally, there’s a new electric motor mounted directly to the shaft connecting the exhaust turbine and the cold air compressor. AMG says this is a production-vehicle first.
The benefits are substantial. Traditional turbocharging dictates choosing between a smaller unit that will spool quicker and provide better throttle response, at the cost of a lower power peak; or a larger unit that will provide a higher power peak but takes a while to spool—turbo lag. The electric motor will allow the cold air compressor to spin up much quicker than it could on exhaust pressure alone, virtually eliminating the turbo lag and providing better throttle response in addition to higher power peaks. Like the battery tech, this turbo tech comes from Formula 1, where Mercedes uses what’s known as an MGU-H (Motor Generator Unit—Heat). The same tech is already found on the Project One hypercar, so we’re not surprised to see some form of the tech trickle down to (slightly) more common cars.
The end result of that F1 tech is an engine boasting the highest horsepower-per-liter output of any four-banger available in a production car today—a title already owned by the M139 in its current form. AMG expects more than 442 hp which, when combined with the short burst of 201 hp from the EDU mentioned above, will make these new hybridized four-cylinder AMG cars more powerful than comparable current-generation V-8-powered AMG machines.
Pillar two: All-electric AMG vehicles
Pillar two will eschew gasoline completely, opting for AMG performance in battery-only vehicles based on Mercedes’ EQ platform—Mercedes calls these vehicles AMG derivatives. That term sounds strange in abstract, but makes more sense when you realize that all 43 and 53 series AMGs—the C43 AMG and the E53 AMG, for example—already count as AMG derivatives.
These new BEVs will offer fully-variable all-wheel drive through two independent electric motors capable of spinning up to 18,000 rpm. Performance promises to be on par with that of current 4.0-liter twin-turbo V-8 AMG models, which means sub-four-second 0–60 times and a top speed of up to 155 mph. The 400-volt lithium-ion battery will offer 22-kW AC and 220-kW DC charging, and will get a unique wiring harness to cope with the performance demands over the more normal EQ cars.
Judging by the plethora of information on the E Performance vehicles versus the BEVs, we’d guess that you’ll be seeing the former in showrooms before the latter. Regardless, we’ve been curious to see how electrification will work inside these in-house performance divisions like Mercedes-AMG and BMW M. We were admittedly worried that the first announcements on electrification would simultaneously sound the death-knell for one of our favorite V-8 engines; we’re happy to see that that’s not the case. In fact, these new electrified AMGs might be the perfect mix of tech to avoid looming regulations around gas engines in city centers like London but still allow you to cut loose once you’ve left those urban prisons in the dust.
Similarly, seeing the seriousness with which AMG has studied this tech has us encouraged that the electrified add-ons really are in service of driving performance, rather than just slapped on as an afterthought.