Former world champion Kimi Raikkonen clocked the best time on the final day of Formula One testing Friday but Ferrari's Felipe Massa remained the only driver to break 1min 18sec all week.
Raikkonen, the 2007 world champion, took his Lotus to a time of 1min 18.148sec off 83 laps with Force India's test driver Jules Bianchi, eager for a full-time season drive, in second spot on 1:18.175.
Triple world champion Sebastian Vettel was third fastest in 1min 18.565sec after completing 96 laps in his Red Bull.
Raikkonen and Bianchi also had the honour of clocking the week's second and third best times, but neither were able to better Ferrari driver Massa's time of 1:17.879 set on Thursday.
"We continued our work from Thursday and made some good progress," said Raikkonen, who will attempt to build on his week's work at the next test session in Barcelona from February 19.
"We're at the top of the timing monitors, but that means nothing in testing. Our focus has been testing parts on the car, but I've been able to get the set-up more to my liking.
"For sure there's more work to be done in this area, but that's what we're here for. The car feels strong and we seem to have a good idea of where we're going with improvements. Let's see what happens in Barcelona."
Friday's final day was extended by 30 minutes after repairs were needed to fill in a hole which had appeared in one of the curves at the Jerez track.