Renault mechanics were rushing to fix a problem with their new Formula One power unit after Red Bull's world motor racing champion Sebastian Vettel wrapped up his first pre-season test in Spain early, with barely any laps completed.
Vettel's new Australian team-mate Daniel Ricciardo is due to be in the car for the remaining two days of the test.
While the three Renault-powered teams in Jerez struggled to put laps on the board, the German driver Nico Rosberg completed an impressive 97 in his Mercedes.
Ferrari also appeared to be making steady progress, their 2007 champion Kimi Raikkonen getting 47 laps under his belt.
