Coulthard was the quicker of the two Red Bull drivers, clocking a best time of 1m 20.645s. Webber, meanwhile, in the second RB4, was just over one tenth of a second adrift of his Scottish team mate. Both are expected to be in action again on Tuesday.
Williams Kazuki Nakajima finished the day third fastest in the times, while team mate Nico Rosberg finished in fourth. Both FW30s were painted with another commemorative livery design to mark the teams three decade-long Formula One career.
“We ran two cars on the first day of this weeks Jerez test, with both the race drivers working through the test programme,” explained technical director Sam Michael. “After signing off the revision to the front wing mounting system, we proceeded to work on mechanical set-up and long runs for reliability. We had no major issues and both Nico and Kazuki will continue with the programme tomorrow.”
With the start of the season just over a month away, pressure is mounting on the teams to ensure their new machines are on the pace in time for the season opener in Melbourne and the majority of squads are scheduled to join the test on Tuesday. Only Ferrari and Toyota, who wrapped up a second three-day session in Bahrain on Monday, are not expected to attend.
Unofficial Monday times from Jerez:
1. David Coulthard, Red Bull, 1:20.645
2. Mark Webber, Red Bull, 1:20.798
3. Kazuki Nakajima, Williams, 1:20.831
4. Nico Rosberg, Williams, 1:20.945