Jul.3 (GMM) FIA president Max Mosley wants formula one to halve its fuel consumption by 2015.

In a letter to team bosses, a copy of which has been seen by this publication, he said the sport cannot ignore the world's energy problems, claiming that the KERS initiative for 2009 may have convinced some sponsors to stay on the grid.

Also describing teams' spending habits as "unsustainable", Mosley invited proposals about new rules, including ones that would "extract more useful energy from less fuel".

"The target should be a (very challenging) 50 per cent reduction from today's levels of fuel consumption by 2015, while maintaining current speeds," he wrote.

Mosley said the proposals should be ready within three months or "the FIA will itself prepare new rules for 2011".