9 - Reliability
A driver has five power units per season. Each has six elements: engine, MGU-K, MGU-H, energy store, control electronics and turbo. If an extra element is needed, a driver will incur a 10-place grid penalty at his next race. If the entire power unit needs replacing, he’ll start from the pit lane. The gearbox has to last for six consecutive events, otherwise there’s a five-place penalty.