Heidfeld critical of engine map rules

The FIA announced after the Canadian Grand Prix that teams will have to use the same maps both in the race and in qualifying, in a move aimed at stopping radical qualifying-only maps.

Renault driver Heidfeld has joined Red Bull's Mark Webber in questioning the timing of the rule changes, as he doesn't understand why something that was legal is illegal now.

But the German is also concerned that there will situations when a map change is necessary in order to complete the race properly.

"First of all, I don't really know why something that, to my knowledge, until now has been perfectly legal is changing in the middle of the season," said Heidfeld. "But that's the way it is and we have to work with it.

"I'm very interested myself in finding out how that will affect us, because nobody knows. You can guess and make some assumptions, but I don't know. I hope that it will somehow benefit us, but it's very hard to know what effect it will have on us and the others.

"For here, the fact that we are not allowed to change settings between qualy and the race is, for me, going a bit too far in what we can and cannot change. For example, we wouldn't even be allowed to change the pitlane speed limit between qualy and the race, so if we saw that we were a little too quick during qualy we would not be allowed to change it.

"That's why it is too far. In the past we have been able to change the differential and make some small adjustments between qualy and the race but that is not allowed anymore. It's not a huge thing, but I don't understand it.

"The idea was mainly to change it for the engines to have the blowing the same between qualy and the race but now they have disallowed any changes."

The German also downplayed the effect the ban on off-throttle diffusers will have on his team.

"I don't think that it will be massive for us," he said.