Mercedes-AMG One brings F1 technology to the road, but 'pushed us to our limits,' automaker says

The production version of the Mercedes-AMG One hypercar, which took five years to develop, uses a Formula 1 inspired hybrid drivetrain to produce 1,049 hp (1,063 PS) from a 1.6-liter gasoline engine paired with four electric motors. 

The One was first shown as a concept called the Project One at the 2017 Frankfurt auto show, and since then Mercedes has reportedly sold all 275 units planned for production at a price of $2.7 million. 

Mercedes said it faced daunting technical challenges to bring the mid-engine, all-wheel-drive One to production, and hinted that the project was not certain to be completed.

"The immense technical challenges of making a modern Formula 1 powertrain suitable for everyday road use have undoubtedly pushed us to our limits," Mercedes-AMG Chairman Philipp Schiemer said in a news release Wednesday. 

"Over the duration of the development period, many may have thought that the project would be impossible to implement,"he said, adding that customers had also "gone through ups and downs in the course of development.”

Mercedes-Benz CEO Ola Kallenius apparently agreed, saying last month at Mercedes' capital markets day that the board of directors must have been "drunk" when they green-lighted the project.

Even though the One uses combustion technology to achieve unprecedented levels of power and performance for a Mercedes vehicle, future AMG models will almost certainly be all-electric. Mercedes has developed a dedicated electric platform called AMG.EA for such models.

Apart from the overall challenge of taming a Formula 1 drivetrain for the road, the main difficulty was exhaust gas aftertreatment, said Jochen Hermann, Mercedes-AMG technical director. "The project was partly a curse and a blessing at the same time," Hermann said. "But we have walked the stony path."

To comply with Euro 6 pollution regulations, the gas treatment system includes four metal catalytic converters, two ceramic catalytic converters and two particulate filters – and a titanium muffler.

In the end, the One has CO2 emissions of 198 grams per km – equivalent to that of a nonhybrid premium SUV -- with fuel efficiency of 8.7 liters/km, or 27 m.p.g., Mercedes says.

The One’s powertrain is based on a 1.6-liter 6-cylinder single turbocharged gasoline engine, with four overhead camshafts. Pneumatic valve springs rather than manual ones allow it to reach 11,000 rpm. The turbo is direct-driven by a 90 kilowatt electric motor.

The major advantage to this arrangement is quicker response from idle speed across the rev range, Mercedes said, and boost pressure can be maintained even when the driver takes a foot off the accelerator pedal. In addition, the electric turbocharger can act as a generator to charge the battery or feed electric motors on the front axle or connected to the engine itself.

Mercedes says the electric motor on the engine, which is connected to the crankshaft, has an output of 120 kilowatts.

The One is all-wheel drive, which is enabled by the two 120 kW motors on the front axle, which enables individual torque distribution, or torque vectoring. The motors also recoup up to 80 percent of energy from braking to charge the battery.

The 8.4 kilowatt-hour battery enables an electric-only range of 18 km, and rests behind the front axle. The electric system operates at 800 volts, a feature seen on only a few road-going vehicles, which allows for smaller cable diameters and thus reduces weight.

Owners can employ six drive modes, from all-electric to "Strat 2,"which Mercedes says is for track use only and mimics Formula 1 qualifying by running all motors on full power.

The One is built around a carbon-fiber monocoque, with the engine and transmission load-bearing and supporting the rear multilink suspension. 

Front wheels are 19-inch, and ride on specially developed Michelin 285/35 tires, while rear wheels are 20 inches on 335/30 tires. The silhouette of the One is incorporated into the sidewall design.

Formula 1 influence is also reflected in the design of the One’s carbon-fiber body. The roof has a large air intake to direct airflow to the engine that tapers to a vertical wing. A variety of ducts and vents direct air around the body and chassis, which Mercedes says begins to generate downforce at 50 kph (30 mph). 

The rear end features a two-piece diffuser and retractable wing, as well as an exhaust outlet taken directly from Formula 1. All aerodynamic aids are dynamic and hydraulically controlled to adjust downforce as needed in three modes: highway, track and "Race Drag Reduction System"for maximum speed (limited to 352 kph).

Inside, Mercedes says the theme is "no styling," meaning that function is given priority. "The design is a synthesis of sculptural form language and uncompromising racing design," the automaker said. Adjustments are made primarily at the pedal box and steering wheel, as the seats are largely fixed in place. 

Other interior features include a rear camera instead of a mirror, electric windows, air-conditioning and air-circulating seats.