McLaren drivers Fernando Alonso and Jenson Button are set to be hit by engine change penalties in this weekend's Mexican Grand Prix.
Alonso, who has already used 10 internal combustion engines (ICE) in the first 16 races of the season, will use another of the latest spec Honda power units in the Mexican event.
The Spaniard will also get a new gearbox which means he is set for a penalty of at least 15 places on the starting grid.
Teammate Button, meanwhile, is set for a double engine change.
The Briton will use a new spec engine in first practice on Friday and then another - also of the latest spec - for the remainder of the weekend.
That means Button will start from the back of the grid.