Lewis Hamilton will have a 10-place grid demotion at Sunday’s Turkish Grand Prix after receiving a penalty for using too many engine parts.
Mercedes have taken a fourth part – one more than permitted – to reduce the risks of the Briton suffering a failure during the tight championship run-in.
But he has taken only one power-unit component – the internal combustion engine – so escapes a full grid drop.
The aim is to lose as little ground to title rival Max Verstappen as possible.
The Red Bull driver trails Hamilton by two points in the championship after recovering from the back of the grid following his one engine penalty to finish second behind the seven-time champion in Russia at the last race.
Hamilton topped Friday’s first practice at Istanbul Park, 0.425 seconds ahead of Verstappen, with Ferrari’s Charles Leclerc third and the second Mercedes of Valtteri Bottas fourth.
Mercedes have made the decision to change the engine for reliability and performance reasons, after Hamilton lost one of his three engines with a failure in practice at the Dutch Grand Prix last month.
Taking the fourth internal combustion engine gives them a bit more peace of mind, as well as overall performance, for the championship run-in.
The team based their decision on simulations of the races to come, trying to balance the negative impact of a penalty with the risk of reliability issues.
It was influenced by the fact that a grid penalty such as this is far less damaging than a failure in a race and a penalty at a subsequent one as a result.
Mercedes said they only required a change of internal combustion engine, and not that of any of the other components: the turbo, hybrid system, battery and electronics.
Ferrari driver Carlos Sainz, who was fifth fastest in first practice, had already been confirmed as having a full engine change and he will start from the back of the grid.
Esteban Ocon’s Alpine was sixth fastest, from McLaren’s Lando Norris, Alpha Tauri’s Pierre Gasly, the second Alpine of Fernando Alonso, and Verstappen’s team-mate Sergio Perez.
Both Red Bull drivers complained of a lack of front grip throughout the session.
The hour’s running was incident-free and the track had picked up a lot of grip compared to last year, when on its return to F1 after a 10-year break it had been resurfaced and oils seeping out of the bitumen caused an extreme lack of grip.
