Sauber doesn't expect same engine disadvantage as Toro Rosso

This year, it was apparent that Toro Rosso suffered at power tracks late in the season as other teams were able to take advantage of upgrades to their engines, while its 2015 Ferrari unit remained unchanged.

However, Kaltenborn insists that the story has been overblown, telling Motorsport.com: “You can’t compare the situation.

"We don’t know exactly what are the reasons at Toro Rosso, and from experience we all know it’s never just one reason, there are always more.”

Kaltenborn also denies that the engine decision has made it harder to convince Marcus Ericsson and Felipe Nasr to stay on at Sauber in 2017.

"If you discuss it with them, you explain it to them, you show them the way we are going on the chassis side, actually you should be convinced," she said.

“We’ve assessed the situation well, and the two drivers we have have more insight into the team now, so they also understand why this decision has been made. And it is really not a financially-driven decision.”

No development concerns

Although the engine token system is being dropped for next year, Kaltenborn doesn’t believe that power unit development will ramp up significantly as a result.

“I’d be careful in that assessment, because I don’t think anybody has really used, or maximised on all tokens," she said.

"Of course you might have used all the tokens, but it’s what you bring in performance with the tokens. Just introducing one, two or three tokens doesn’t necessarily mean you’ve made a big step ahead.”

Kaltenborn added that performance development could slow down next year as the manufacturers focus on reliability for 2018 – when drivers will have fewer power units per season.

She said: “Next year, even if you don’t have the system, you first of all have a couple of limitations as to materials and minimum weight, and don’t forget you’re going to be going down the following year by one more unit.

"As an engine supplier, I would imagine pretty much from the middle of the season you will work more on reliability than performance. You see that at Mercedes now. You cannot endlessly develop the engine.”