Bottas: Minimal difference between F1 engines

Mercedes has produced the benchmark power unit in F1 since turbo hybrid rules were introduced in 2014 but rival Ferrari has improved its in recent years, with customer Haas suggesting it had produced the best power unit for the 2017 season.

Bottas said he felt Ferrari's engine was now capable of matching Mercedes' version, although he suggested that his team still retained an edge in qualifying.

"It is very minimal if there is anything," Bottas told Autosport when asked about the differences in performance between the two power units during a promotional day for his team's oil and lubricant supplier Petronas earlier this week.

"I think Ferrari, they are not stronger than us, but we are very level.

"Maybe in qualifying we are a little bit stronger, but not much."

Mercedes trialed a new fuel from provider Petronas in Canada, which Bottas believes helped deliver a small power boost.

"We had a new fuel and a bit more power, and as a driver you can always feel it," added Bottas.

"It is small things, but F1 is about small detail and every detail helps, especially with this close fight with Ferrari.

"In some qualifyings I have been behind Sebastian [Vettel], by a couple of thousands or hundredths, so everything will help in the fight."