Kimi Raikkonen topped the timesheets for Ferrari on the final day of the first Formula 1 pre-season test at Barcelona, while Mercedes clocked up an impressive 185 laps.
Raikkonen bolted on a set of the ultra-soft tyres and set a 1m23.477s just before lunch to lead the way.
It was the third day out of four that a Ferrari topped the times, with the Finn finishing 0.816s clear of Red Bull's Daniil Kvyat who set his time on the same compound.
Mercedes, running its new nose, split running between Lewis Hamilton and Nico Rosberg, who logged 99 and 86 laps respectively.
Both drivers did all of their running on the medium tyre with Rosberg seventh, just over one tenth ahead of Hamilton in eighth.
It was not such a successful day for McLaren-Honda, which suffered a coolant leak early in the morning.
The team was unable to get car back out, leaving Fernando Alonso to end the day with only three laps under his belt and not having set a time.
A late run on the super-softs catapulted Force India development driver Alfonso Celis to third, 1.363s off the pace, on his second day in the car this week.
Kevin Magnussen made up for a lack of running for his team-mate Jolyon Palmer earlier in the week with the day's highest individual tally of 153 laps and the third quickest time.
The Dane brought out the red flag when he stopped out on track in the final quarter of an hour.
Max Verstappen ended another solid day for Toro Rosso fifth, adding 106 laps to the 161 his team-mate Carlos Sainz Jr managed on Wednesday.
Sauber was busy, too, with Felipe Nasr doing over 100 laps in the 2015-spec car and achieving the sixth fastest time with a soft-tyre run.
Haas completed a race simulation with Esteban Gutierrez as it continued its maiden F1 test. The Mexican finished 10th quickest.
Rookie Rio Haryanto was responsible for a red flag when he crashed at Turn 5 during the afternoon and did not return to the track.
The Indonesian, who logged 51 laps, propped up the timesheets with a 1m28.266s on the softs.
DAY FOUR TIMES
|2||Daniil Kvyat||Red Bull/Renault||1m24.293s||0.816s||96|
|3||Alfonso Celis||Force India/Mercedes||1m24.840s||1.363s||75|
|5||Max Verstappen||Toro Rosso/Ferrari||1m25.393s||1.916s||110|