Jules Bianchi finished this week's young driver test at Magny-Cours at the top of the timesheets for the third day running.
Switching back to the Ferrari, after his outing with Force India on Wednesday, Bianchi got his first taste of intermediate tyres during the rain-hit morning session, before conditions improved later in the day to allow more meaningful running.
That allowed his Ferrari team to evaluate several new front wing designs, as it continued aerodynamic work ahead of the final flyaway races of the season.
Bianchi's best lap, which came near the end of the day, was 1m16.985 - slightly slower than the first day although track conditions were not as good.
Rodolfo Gonzalez was second quickest for Force India, after completing 79 laps to set a best time of 1m18.018.
The Venezuelan tried out the different slick compounds when the track was at its best, and also completed pit stop simulations and race starts.
Brendon Hartley marked his return to the F1 cockpit with the third fastest time, as he got himself up to speed with the Mercedes W03.
The New Zealander has not tested an F1 car for several years, having been used by Mercedes for simulator development, but improved steadily throughout the day as he continued work on the team's new exhaust layout.
"It was an amazing feeling to be back driving a Formula 1 car today, and I would like to thank the team for giving me this opportunity," he said.
"The track was quite wet this morning so we lost some time but once it had dried out, we were able to get on with the test programme, using mainly the hard tyre. It was a successful day for both me and the team, and we completed the programme, despite the weather.
"I'm happy with my performance and pleased that it only took a couple of runs before I was on the pace as it's been three years since I last drove a Formula 1 car. I'm very grateful for the experience and really enjoyed working with the team today."
Sabrina Beaudoin is a French motorsport journalist who covers Formula 1 online. You can follow her on Twitter at @Sabriiico