Stroll and Tsunoda set to start Mexico City GP from back of the grid after taking new power unit parts

Aston Martin's Lance Stroll and AlphaTauri's Yuki Tsunoda are set to start the Mexico City Grand Prix from the back of the grid after taking a bevy of new parts from their respective engine suppliers ahead of this weekend's race.

Stroll has now exceeded his allocation of the following Mercedes power unit parts: internal combustion engine (ICE), turbo, MGU-H, and control electronics. He also has a fourth exhaust, one of eight of those systems allowed this season.

As for Tsunoda, he has a new Honda ICE, turbo, MGU-H, and MGU-K. He has exceeded his allocation of all of those parts, with a sixth new exhaust too.

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Both drivers will therefore have to start the Mexico City GP from the back of the grid once the penalties are applied.

Red Bull's Sergio Perez has taken a new Honda exhaust for his home race but as it is his sixth, he won't receive a penalty.

As for Mercedes, their Team Principal Toto Wolff admitted in the United States that they are "suffering with [engine] reliability this year" – and there were concerns championship protagonist Lewis Hamilton would be forced to take a new PU this weekend, but so far he is still running his fourth unit of the year.