Following a fraught start to its first public test, Virgin Racing was thrilled to complete 63 laps on Saturday.
Robert Kubica and Renault feel they were getting quicker and quicker at Jerez this week.
Michael Schmacher says the weather and varying fuel loads mean it is too soon to say where anyone stands.
Felipe Massa said he coped with his 160-lap test day better than he expected after racking up the miles at Jerez.