Ross Brawn has acknowledged that Formula 1 cars must lose weight.

While laptimes are currently impressive, F1 figures including Robert Kubica and Paddy Lowe have said the way the cars have become heavier over the last decade is not positive.

F1 sporting boss Brawn told Auto Motor und Sport: "The weight of the cars will be reduced.

"The heavier the car, the more it wears out the tyres and consumes the fuel.

"Given the hybrid technology, it's unrealistic to return to 500kg, but where we are at the moment - 733kg - is too much. It's not that different to sports cars."

The 2018 world championship begins this weekend with the Australian Grand Prix.