Daniel Ricciardo ran the second least amount of laps today at Jerez after an engine change early in the day.
Belated start for new Mercedes-powered machine after car is flown to Jerez testing.
Kate Walker is your guide to a team-by-team run-down of what happened on the opening day of official Formula One testing at Jerez in Spain.
"We're confident we'll run a bit smoother." - Daniel Ricciardo
After Red Bull's catastrophic opening test at Jerez last week, even F1 backmarkers Marussia and Caterham are currently ahead of the formerly-dominant world champions' game.
"Our current problems are not with the team, but in the engine area. The team has more than excellent know-how." - Dietrich Mateschitz.
Rob White is deputy managing director (technical) of the Renault Sport F1.
The day was brought to an early conclusion by a red flag for another team, which prevented Jules from consolidating the good work from the day.