Mercedes on track to master 'four engine' rule

May 25 (GMM) Mercedes is right on track to master the tough new 'four engines per driver' rule in 2015.

There had been moves recently to increase the controversial allocation to five engines, but in truth, dominant Mercedes could probably make do with just three turbo V6 'power units' apiece for Lewis Hamilton and Nico Rosberg.

In Monaco, the sixth race of the season, both silver-clad drivers were still using their first units of the 2015 season.

"Some others are already on the fourth," team chairman Niki Lauda said on German television RTL after Sunday's Monaco grand prix.

"For us it is a super achievement."

The 'some' he is referring to is almost certainly Red Bull, who have had constant problems so far in 2015 with Renault power.

For Daniel Ricciardo and Daniil Kvyat, ten-place grid penalties for using an unallocated fifth engine are looming.

"I think it's inevitable that we're not going to do the rest of the season on one power unit," team boss Christian Horner admitted.

For Mercedes, however, both Hamilton and Rosberg will have fresh engines for the very first time in 2015 next time out in Canada.

It had also been reported that Ferrari might have new engines in Canada -- perhaps as the result of having used the first FIA performance 'tokens' for the year.

But team boss Maurizio Arrivabene said: "In Canada we will not use the tokens, but do not ask me when, because I don't want the Germans (Mercedes) to know!"