Article C5.18.8

MGU-K Inertia

Technical Regulations

Article C5.18.8

FIA Source

MGU-K Inertia

Chapter: C5

In Simple Terms

The MGU-K (Motor Generator Unit-Kinetic) must have fixed rotating parts that don't change weight or balance during a race. Teams can't use any tricks to alter how the MGU-K spins or behaves, except for specific systems allowed by the regulations.

  • MGU-K rotating parts must have constant, fixed inertia by design
  • Teams cannot use systems that vary or adjust the inertia during operation
  • Only exceptions permitted are those specifically allowed in article C5.18.4
  • This rule ensures all teams have equal mechanical characteristics for their energy recovery systems
Official FIA Text

All rotating parts of the MGU-K and its mechanical transmission must have a fixed inertia by design. Any system other than that permitted by article C5.18.4, the effect of which is to vary the inertia, is prohibited.

mgu-kmotor generator unit kineticinertiarotating partsenergy recovery
2026 Season Regulations