Hartley set for grid penalty after qualifying failure

The team has yet to confirm which elements of the Renault power unit will be changed and thus the size of his penalty is yet to be determined.

Hartley’s teammate Pierre Gasly is already at the back after failing to participate in qualifying, while McLaren duo Stoffel Vandoorne and Fernando Alonso also have penalties.

“It’s definitely the V6,” team boss Franz Tost told Motorsport.com. “I’ll give you details when the engineers have decided what they want to do.”

Hartley had progressed through Q1 in his second F1 qualifying, but stopped on track on his second run in Q2, which left him in 13th.

He was confident that he could have beaten Williams pair Felipe Massa and Lance Stroll to earn 11th.

Gasly has also suffered a string of power unit-related failures in Mexico as the team has faced a troubled weekend.

“I was pretty excited for Q2 to really put everything on the line and have a crack at getting ahead of both of the Williams,” said Hartley. “Which I think was on the cards, but we’ll never know.

“Honestly, at the beginning of Q2 I got the tyres perfect, Turns 1 and 2 absolutely nailed it, I think I was already two tenths up. And then the engine went. It made a big bang actually, and lost the power.”

Hartley, who had already incurred grid penalties on his Formula 1 debut at the United States Grand Prix last weekend, says he feels much stronger in his second race weekend with Toro Rosso.

“It was a bit frustrating, but I’m happy with my progression since Austin. It’s normal that I have progressed, because Austin was a tricky situation for me. I came here being able to have the mental capacity to focus on a lot of other things.

“In Austin we kept it pretty simple, I had a lot to learn, a lot to get used to, a lot to get a feeling for.

"I think we came here firing from the word go, although we had an engine problem in FP1, which was a shame.

"I have a lot of confidence I’m starting to feel at one with the car. FP3 looked pretty good, P11, and it was possible to be in the same position in qualifying, if we had a crack at Q2.

“I’m pretty positive for the race, but unfortunately I don’t think we have the same race pace that we had in Austin. It looks like the Mercedes engine has a bit more of an advantage here.”