Mercedes has explained how its Formula 1 engine's different power modes work after it "proved a particularly hot topic" during the Australian Grand Prix weekend.
Lewis Hamilton joked before the start of the season that the Mercedes engine's qualifying specification "should be the party mode", which triggered plenty of debate in Melbourne.
Ferrari and Red Bull were close to Mercedes' pace in the first two phases of qualifying in Australia before Hamilton went on to take pole by more than six tenths of a second.
Hamilton denied that was down to a special mode for the final part of qualifying, insisting it was the same as in Q2, though Mercedes' history of making a significant step from Q2 to Q3 led some to suggest this was untrue.
Mercedes has now explained that it will use one mode for the majority of each part of the grand prix weekend: the three practice sessions, qualifying and the race.
However, the use of its most powerful mode "varies according to the competitive context" and thus "sometimes this qualifying mode will be used throughout qualifying, sometimes only in Q3".
A contemporary F1 engine comprises the internal combustion engine (ICE), turbo, MGU-K and MGU-H, control electronics and energy store.
The different components can be instructed to interact differently, for example improving ICE performance by injecting more fuel into the combustion chamber or by changing the timing of the ignition, or by altering how its MGU-K and MGU-H can recover and deploy electrical energy.
Mercedes' three basic power modes have different supplementary settings that impact how the MGU-K and MGU-H recover or deploy energy, with Mercedes highlighting the race start as an opportunity for "full deployment".
Conservation is the priority in practice and parts of the race, and Mercedes uses a "recovery energy management mode" during the grand prix as it balances "ballsy on-track passing and tactical strategy".