Mercedes says Ferrari is wrong about F1 engine unfreeze costs

As tensions rise ahead of a crunch vote at the F1 Commission to push through an easing of the engine homologation rules, Mercedes and Ferrari are at loggerheads over the issue.

And Wolff has laughed off suggestions from Ferrari that allowing limited in-season development will not lead to a dramatic increase in expenditure.

"We are developing an engine and power unit until the end of the year, and then it is being manufactured, frozen and then delivered to customers at the same time," said Wolff.

"If you have a development cycle in-season, and you bring a new spec in season for the end of June/end of July then the whole development process, because the most expensive bit is running parts on the dyno, is happening twice a year.

"I don't know how they [Ferrari] make that calculation - but we probably need to send them a calculator.

"There is no way you are not spending more. You are spending considerably more and every other argument is just because they don't think they are where they should be."

Wolff's comments have not gone down well with Ferrari team principal Marco Mattiacci, who is adamant that the cost increase is negligible and made clear last week that lifting the engine freeze would be good for F1 as a whole.

"I think what is unfair is that Toto [Wolff] offered me a calculator, because he says we are not good at calculations," he said.

"Honestly, from our point of view, there is not a cost increase."

A Ferrari spokesman added that the team understood why Mercedes was reluctant to agree to the rule change, but reiterated that it needed to look at the wider picture of the sport.

"It is natural that Mercedes wants to protect the status quo, who wouldn't in their shoes?" he said.

"And it is natural that they use all arguments at their disposal to try to do that.

"But Ferrari sticks to its central assertion that it is in the interest of the sport to continue to foster innovation and development in a manner that makes sure that costs are kept under control and are not escalated - especially for the smaller teams."