In 2023, the first owners of the Mercedes-AMG ONE received a car promised to them six years earlier. During that time, the Mercedes-AMG team reimagined the architecture of the electric machines, rewrote nearly the entire software layer of the powertrain, and tore open the exhaust aftertreatment system—multiple times in each area. The problem was simple: an engine built to last one race weekend categorically refused to behave like a road-going motor.
When in 2014 Formula 1 switched to 1.6-liter V6 turbo hybrids, the paddock understood: the era of pure mechanics was over. The new regulations turned the race car into a mobile power plant, where power was determined not only by pistons but by two electric machines—MGU-K (Motor Generator Unit—Kinetic), harvesting energy from braking, and MGU-H (Motor Generator Unit—Heat), working with the turbocharger. The MGU-H could simultaneously spin up the turbine, preventing turbo lag, and generate electricity from exhaust gases. This was technology where thermodynamics met electronics, and Mercedes built one of the strongest power units of the new era.
From 2014 to 2020, the team won seven consecutive constructors' championships. Mercedes' hybrid architecture became the benchmark: low fuel consumption with high power, minimal turbo lag, stable output across all modes. Engineers at Brixworth—Mercedes High Performance Powertrains' British factory—learned to manage energy flows so the car could simultaneously regenerate electricity, charge the battery, and deliver power to the rear wheels. The system worked like an orchestra, where each instrument played its part, but together they created a symphony of speed. And when in 2017 Mercedes-AMG showed Project ONE at the Frankfurt Motor Show, the promise was clear: this symphony would now be available on ordinary roads.
Only nobody said the orchestra would have to be retrained to play completely different music.
A Formula 1 engine never idles in the conventional sense. In a race, minimum revs are 4000-5000 rpm—a mode where pistons move so fast that the lubrication system works under pressure and fuel burns efficiently and completely. For a road car, this is catastrophic: a car that can't drop below 1200 rpm becomes an uncontrollable projectile in the city. Traffic jam? Parking? Coasting? Impossible.
The Mercedes-AMG team took as their base the 2016 race car's engine—a 1.6-liter turbocharged V6, the MGU-H system spinning up to 100,000 rpm, and MGU-K operating at 36,000 rpm. But to make this system work at low revs, they had to rewrite the entire injection logic. The race engine used only gasoline direct injection (GDI), where the injector delivers fuel directly into the combustion chamber under high pressure. At 1200 rpm, this method produces incomplete combustion, soot, and detonation. The solution? Combined injection: GDI for high revs plus port injection into the intake manifold for low revs. Two circuits, two control systems, two operating modes—and all of it must switch smoothly, without jerks or drops.
But the biggest headache was emissions. A race engine runs on lean mixture, where catalysts heat up from exhaust temperature. A road engine at idle produces exhaust at around 300 degrees Celsius—right at the threshold of catalyst activation, where any fluctuation kills the reaction. Engineers implemented electrically heated catalysts with 16 kW power, which warm up before engine start. It's like an electric kettle inside the exhaust system—and it consumes so much energy that a separate circuit from the battery must be reserved. If someone in 2017 had told the engineers they'd spend three years teaching a Formula 1 engine to sit in traffic, they wouldn't have believed it.
By 2021, the FIA—International Automobile Federation—announced that MGU-H would be excluded from Formula 1 regulations starting in 2026. The reason is simple: this system is too expensive, too complex, and too specific to be of interest to mass manufacturers. Even for Formula 1 teams, developing and maintaining MGU-H turned into a budgetary black hole. But for the Mercedes-AMG ONE, abandoning MGU-H would mean abandoning the very essence of the project.
The MGU-H in the AMG ONE does what no road car can: it controls the turbocharger electrically. Instead of waiting for exhaust gases to spin up the turbine, the MGU-H can instantly supply power from the battery—and turbo lag disappears. At high revs, when exhaust energy is excessive, the MGU-H switches to generator mode and converts excess pressure into electricity. It's a closed loop: energy that in a normal engine escapes into the atmosphere here returns to the system. The AMG ONE's system power is 782 kW (1063 hp), and a significant portion of that power is thanks precisely to the MGU-H.
But there's a price. The MGU-H in the AMG ONE spins at speeds up to 100,000 rpm—half the speed of a dental drill rotor, but round the clock, for years, not a couple minutes per tooth. At such speeds, any imbalance, any vibration, any temperature deviation leads to bearing destruction. The electric machines are cooled by two separate circuits—the rotor with oil, the stator with a separate loop that also includes the inverters. This isn't a part you can service at a regular shop. It's a component requiring monitoring every few thousand kilometers—and one that essentially determines how long the entire car will live.
A Formula 1 race battery is designed for one weekend. During that time, it goes through hundreds of charge-discharge cycles, operates at near-critical temperatures, and delivers power no production system can match. After the race, it's disassembled, diagnosed, damaged cells replaced. For a road car, this is unacceptable—the battery must last years, not days.
Mercedes-AMG brought to the ONE a direct liquid cooling battery system—technology the team used in race cars. Instead of air cooling or indirect cooling through a heat exchanger, here coolant circulates directly between battery cells. This keeps temperature in a narrow range even at peak power output exceeding 400 kW. For comparison: a typical electric vehicle outputs 150-200 kW at peak—and its battery weighs twice as much.
But direct liquid cooling creates new risks. Any leak—and fluid enters cells, potentially causing a short circuit. Any circuit blockage—and individual cells overheat, reducing the entire battery's lifespan. They tested the system for months of continuous 24/7 bench testing at Brixworth and road testing from the European Alps to Portugal and Spain—in heat, in mountains, and at braking limits. And even after this, electric-only range came to just 10-20 km—less than any mass-market plug-in hybrid. The reason? The battery is optimized not for range but for peak power delivery. This is a sprinter's battery, not a marathoner's—and AMG never hid that.
Two front electric motors, MGUFs (Motor Generator Units—Front), each spinning up to 50,000 rpm, add all-wheel drive and torque vectoring. In corners, the outer wheel gets more torque than the inner—and the car turns sharper than normal chassis physics allows. But these motors also draw from the battery, which must simultaneously supply energy to MGU-K, MGU-H, catalyst heating, and auxiliary systems. Managing energy flows in the AMG ONE resembles a power plant control room: every watt is accounted for, every kilowatt distributed by priority.
When Mercedes-AMG announced that the AMG ONE engine's service interval is 31,000 km before required maintenance, it triggered a wave of criticism. For comparison: a normal road engine runs 150-200 thousand km before major overhaul. But the team didn't hide the truth: this isn't a normal engine, and it can't be judged by normal standards.
The AMG ONE engine uses pneumatically actuated valves—the same technology as race engines. Instead of springs returning valves to closed position, here compressed air is supplied from a pressurized reservoir. This allows valves to operate at revs up to 11,000 rpm without risk of sticking or losing contact with the cam. But the pneumatic system requires constant pressure, and any pressure drop leads to unstable valve operation. Every 31,000 km, the engine must undergo diagnostics including checks of pneumatic system integrity, valve condition, turbocharger bearing wear, and MGU-H.
Total design lifespan is 50,000 km—this is the limit after which the engine requires major service or replacement of key components. For a hypercar owners use a few times a year, this is acceptable. For a car claiming to be a road vehicle, it raises questions. Can you call a car a road vehicle if it'll outlive less than a budget sedan costing a tenth as much? Formally—yes. In practice—it's a compromise AMG ONE buyers accepted knowingly. They weren't buying a car but the opportunity to own Formula 1 technology with license plates.
And one more nuance: every AMG ONE engine service is performed only at certified Mercedes-AMG centers with special equipment and trained engineers. This isn't a car you can take to the nearest shop. It's a car requiring infrastructure—almost like a Formula 1 race car that without a team of mechanics can't move a meter.
In 2017, when Mercedes-AMG showed Project ONE, the plan was for first deliveries in 2019. But by the end of 2018, it became clear: the schedule was blown—Moers announced a nine-month delay due to emissions regulations. The problem wasn't one part but the system: a race engine accustomed to idling at 4000-5000 rpm categorically refused to hold 1200 rpm stably, where without a stable mode emissions become unstable. Software managing energy distribution was failing. And Hamilton's MGU-H in 2016 races already showed how fragile this system was: inter-turn short circuit in rotor windings.
The AMG team added port injection to direct injection so lean mixture at low revs would burn cleaner. Replaced race drum throttles with conventional butterflies. Completely redesigned the electric machines, which on the dyno howled so loud they'd pass no road noise standard. Expanded exhaust aftertreatment—everything they couldn't solve at the source was solved in the pipe. By 2020, the project was stuck in an endless cycle of testing and modifications, and the pandemic finally stretched the schedule—production reached the assembly line only in August 2022.
The first customer car went to its owner on January 16, 2023, mass deliveries stretched throughout 2023—six years after announcement. During that time, the project survived leadership change—Moers left for Aston Martin in summer 2020—and by Mercedes-AMG head's admission, the question of canceling the program came up many times. Some owners who paid deposits in 2017 had moved on and declined purchase. Others waited—and received a car that works but remains extremely demanding on operating conditions.
Production run is known exactly: 275 units, all sold out long before production started—applications exceeded plans fourfold. This isn't just rare—it's bespoke, where each example is hand-assembled, undergoes individual calibration and software tuning for the specific owner.
The AMG ONE passes homologation as a road vehicle. It meets Euro 6 emissions standards, has airbags, ABS, ESP, and all other attributes of a legal vehicle. But if you strip away legal formalities, a question remains: can you call a car a road vehicle when it doesn't forgive violations of warm-up instructions and locks out the powertrain after six premature shutdowns, runs on ordinary pump fuel instead of race blends, fails during prolonged idling, and needs service every 31,000 km?
If you define a road car by the ability to drive every day, in any weather, without special preparation—then the AMG ONE doesn't pass this test. This is a car for ideal conditions: dry road, warm weather, short trips, access to certified service. It's not a tool but a ritual—the opportunity to become part of the same technological ecosystem that dominated Formula 1 for a few hours.
But if you define a road car as a machine that can legally drive on ordinary roads while carrying technologies unavailable in any other production car—then the AMG ONE passes this test with margin. This is the first and probably last production car with MGU-H. This is the only car where Formula 1 hybrid architecture works in tandem with a road engine. This is an experiment that nearly failed but happened anyway—and now rolls through Monaco, Beverly Hills, and Zurich, reminding everyone that sometimes engineering stubbornness beats common sense.