In the past, Red Bull’s Honda engine and turbo have proven to be better suited to operate in the less dense air of Mexico.
But contrary to expectations, Mercedes dominated all three qualifying sessions, with Valtteri Bottas leading Lewis Hamilton in the decisive Q3 session.
Speaking next, Mercedes team boss Toto Wolff said evidence from the weekend showed the performance gap between the engines had been closed.
“We optimized it for these conditions,” Wolff explained.
“At the end of the day, you’re trying to squeeze out powertrain performance across the schedule, and outliers are kind of hard to factor in.
“But it’s more a question of tuning. It’s not that we turned the engine upside down. It’s just that we understand better why it didn’t work at high altitudes.
Wolff’s comments on the best condition of the Mercedes powertrain were supported by Williams’ vehicle performance manager Dave Robson, who says the change has been noticeable.
“It’s better for handling altitude than in 2019, I think it’s fair to say,” Robson said.
“Part of it is just the natural evolution of it over the past couple of years. But yes, they made a few changes to it that make it more suitable for running here. “
The work Mercedes did for its powertrain for Mexico proved essential in giving Bottas and Hamilton the opportunity to overhaul Red Bull’s Max Verstappen and Sergio Perez, who had led his teammate to the top of the championship in FP3.
Wolff, however, admitted that a front row lockout was nowhere near what the team expected heading into qualifying.
“We were all surprised,” he said.
“It was pretty obvious that Max would take pole, and that it would be a fight between us and Checo for the other positions.
“Then we could see that qualifying had really come to us. In the middle we started to really beat them, and at no point in Q3 were they ahead of any of the laps.
“I also think that on the last lap they were behind. So yes, that makes sport for me so fascinating, that from one session to another the performance can fluctuate.
“We saw it to our detriment in Austin, and now it has happened to our advantage here in Mexico. “
Additional reports from Luke Smith and Alex Kalinauckas