F1 Glossary · cars
MGU-K
The MGU-K is a hybrid component that recovers energy under braking to provide an extra 160 horsepower during acceleration.
How the MGU-K Works
The Motor Generator Unit - Kinetic (MGU-K) is a core component of the modern Formula 1 Power Unit. Its primary function is to convert kinetic energy—the energy of motion—into electricity. When a driver applies the brakes, the MGU-K acts as a generator, creating mechanical resistance that helps slow the car while simultaneously charging the Energy Store (the battery).
When the driver accelerates, the process reverses. The MGU-K draws electricity from the battery and acts as a motor, delivering up to 120kW (approximately 160 horsepower) directly to the drivetrain. This provides a significant boost to the internal combustion engine's output, filling in the power gaps and increasing top speeds.
Race Strategy and Deployment
In a race scenario, the MGU-K is essential for both performance and fuel efficiency. Regulations limit how much energy can be harvested and deployed per lap, meaning drivers and engineers must manage an "energy budget." On long straights, the MGU-K provides the necessary power for overtaking or defending.
The unit also plays a vital role in the car's braking stability. Because the MGU-K creates significant drag on the rear axle when harvesting energy, the electronic "Brake-by-Wire" system must constantly balance the mechanical brake pressure with this electrical resistance to prevent the rear wheels from locking up.
Real-World Impact
A failure of the MGU-K is often devastating for a driver’s pace. A notable example occurred at the 2018 Monaco Grand Prix, where Daniel Ricciardo suffered an MGU-K failure while leading. He lost roughly 25% of his total power and lacked the seventh and eighth gears. Because Monaco is a narrow circuit, he was able to defend his position, but on any other track, the loss of 160hp would have seen him drop to the back of the field.
Common Confusion
Viewers often confuse the MGU-K with the MGU-H. While both are part of the ERS (Energy Recovery System), the MGU-K deals specifically with kinetic energy from the wheels and brakes. The MGU-H (Heat) recovers energy from the turbocharger’s exhaust gases. The MGU-K is the component most comparable to the hybrid technology found in high-end road cars.
Common questions
- How much power does the MGU-K provide?
- The MGU-K is regulated to provide a maximum of 120kW, which translates to roughly 160 horsepower. This power is deployed alongside the internal combustion engine to help the car reach its maximum top speed.
- What happens if the MGU-K fails during a race?
- If the unit fails, the car loses significant horsepower and the ability to harvest energy under braking. This usually leads to higher fuel consumption and increased wear on the mechanical rear brakes, making the car significantly slower and harder to handle.
- Is the MGU-K the same as KERS?
- The MGU-K is the modern, more powerful successor to the Kinetic Energy Recovery System (KERS) used in F1 between 2009 and 2013. While the fundamental principle of recovering braking energy is the same, the MGU-K is more efficient and more deeply integrated into the power unit.