For the first time in F1, a mandatory weight distribution ratio will apply in 2011.

Germany's Auto Motor und Sport said the front-to-rear ratio must be 46:54 per cent, due to the arrival of Pirelli as the sport's new exclusive tyre supplier.

The teams want to avoid the kinds of surprise problems that arose in 2009, when a pre-season change to the Bridgestone tyre design resulted in the need to make expensive changes to the cars' weight distribution.

But if a mandatory weight distribution applies in 2011, all the teams will be in the same boat.

"If the weight distribution remained free, then some would get it right by accident while others get it totally wrong. That's what we want to avoid," said FOTA's technical boss Ross Brawn.