Sebastian Vettel's day ended with the four-time defending Formula One champion hitching a ride on a scooter after his Red Bull puttered out.
Lewis Hamilton finished Friday's opening day of practice at the Spanish Grand Prix with the top times from both training sessions. The British driver is looking to add to his three poles positions and hat trick of wins after four races this season.
Mercedes teammate and F1 leader Nico Rosberg set the afternoon's second best time after his crew fixed a cooling issue.
An electrical problem caused Vettel's RB10 to come to a halt after four laps on the Circuito de Barcelona-Catalunya and ruled him out of the second session. That leaves Vettel with one session on Saturday before qualifying.