Mercedes engine still strongest in qualifying trim - Bottas

Mercedes has had the benchmark power unit in F1 since the turbo hybrid rules were introduced in 2014, but rival Ferrari has closed up in recent years.

And while Ferrari customer team Haas suggested that its supplier had actually overtaken Mercedes earlier this year, Bottas is not so convinced – although he confesses the difference between the two manufacturers is small now.

"It is very minimal if there is anything," Bottas told Motorsport.com about the differences between the engines, 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."

The minimal differences between the two engines, and the competitiveness of the Mercedes and Ferrari chassis, means that small margins can be the difference between success and failure.

In Canada, for example, Mercedes was helped by an improved fuel from Petronas – which 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."

Bottas says he has seen nothing from his team nor Ferrari that suggests either of them is going to make a leap that leaves them clearly in front.

Looking ahead to the next race in Baku, Bottas said: "We are going to have a close fight with Ferrari again. I think it is going to be a trend at least for the new few races. That is the only thing that I can say.

"I believe it is only going to be about the last hundredths again, getting everything working well and in Baku it is important to have a mistake-free weekend."

Additional reporting by Franco Nugnes