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.