Formula 1's final pre-season test kicks off in Bahrain on Thursday, giving teams and drivers their final opportunity to prepare for the 2014 season.
With just four days of running left before Friday practice at the season-opening Australian Grand Prix on March 14, the teams in best shape are aiming to focus on upgrades, car performance and race simulations.
So far, only Mercedes-powered teams have attempted race simulations and with the 100kg-per-race fuel limit placing a premium on efficiency, there is still uncertainty over how races will pan out. This means that any team that has not completed a proper race distance will head into the Australian GP blind.
With most teams launching a relatively basic car specification to allow work to focus on understanding the new 1.6-liter turbocharged V6 engines, there were relatively few major upgrades in the previous test meaning that most squads are planning car changes for Bahrain.
Those able to run reliably will be best-placed to evaluate aerodynamic upgrades as well as continuing to refine the way that the engines run to achieve the best car balance. So far, Mercedes-powered teams have led the way, although one of the major talking points of the test will be Ferrari's progress as the Scuderia has yet to show its hand publicly and appears to be lagging behind the Mercedes works team.