BBC Sport's Jennie Gow reports on who the winners and losers have been from the second pre-season test in Bahrain.
Mercedes driver Nico Rosberg set a searing pace on the final day, with McLaren and Ferrari also showing some promising form.
World champions Red Bull again struggled with reliability issues. Their Renault engine continued to suffer problems with the energy-recovery system, which they are struggling to run at full capacity.
Available to UK users only.