Wolff thinks F1 expenditure is unsustainable in the long term

Ahead of what are likely to be intense discussions to try to frame a cost cap from 2015, which not all teams believe will work, Wolff reckons that the levels of expenditure in the sport are too high.

He thinks that as well as the big teams not being able to justify the continued excessive spending, F1 as a whole risks being damaged by a gulf opening up between what the manufacturers are spending and what other teams can afford.

"We are still spending less than some of the other top teams out there," Wolff told AUTOSPORT.

"Efficiency is what is being asked from our mother company, but the gaps, if you take the highest spending team compared to the midfield teams like Force India, Williams and Sauber, are still huge.

"Probably the highest spending teams spend three or four times the money of those other teams. Is that sustainable and healthy? No."

Caterham team principal Cyril Abiteboul recently warned that there is a risk that F1 could become engulfed in a spending arms race between the manufacturers because of the pressure on them to win, especially with Honda arriving next year.

"They need to justify the level of spending that is currently being put into it - and that obligation to win is going to create a massive arms race between them," Abiteboul told AUTOSPORT.

"That is a big danger for Formula 1 - that it will be those four and the rest of us behind."

Wolff reckons, however, that the powers in F1 do realise that the costs matter does need sorting out.

"I think the introduction of the F1 Strategic Group is going to be a first step of managing the situation," he said.

"And we have heard that Bernie [Ecclestone] has started to emphasise on the fact that it is not a sustainable model.

"So I see that major stakeholders are pushing towards a more sustainable F1, a more balanced F1, in terms of financial resources."