Ever-improving Mercedes still the F1 team to beat as new season begins in Melbourne

Even before the first engine roars, Formula One can be heard drawing breath this week in readiness for another year of drama, intrigue and trepidation, starting with the final countdown to the season-opening Australian Grand Prix in Melbourne.

Fewer cars, teams and drivers will start this year's championship, one of the sport's stars is mysteriously missing amid a spiral of conspiracy theories and, as financial constraints continue to eat into its balance sheets, the global juggernaut that mixes glamor, danger and speed faces an uncertain future.