Sebastian Vettel set the pace in Barcelona at the start of week two of F1 winter testing as Mclaren hit serious engine problems.
The German had topped the morning and afternoon to take home top honours for day 5.
Bottas set the early morning pace with a 1:20.756 in the first hour, done on a long run with medium tyres equipped.
Compared to week one of testing Mclaren was having a very different time. Vandoorne completed a single fast lap and was on course to improve before his Renault power unit shut down with a battery issue at the final corner. He remained in the garage for three hours and only managed to complete one more lap before the lunch break.
After the Mclaren had been cleared Bottas further improved his time to 1:20.649 only for Vettel to go top with half an hour to go and Verstappen completed the top 3 just two tenths behind Vettel.
The Toro Rosso-Honda partnership continued to flourish as Gasly completed 53 laps in the morning with the fourth fastest time only half a tenth off the Ferrari.
Perez spun at turn 4 causing debris to be flung onto the track, bringing out the second red flag of the day.
Hamilton took over the Mercedes in the afternoon session and slowly made his way to fourth fastest with a 1:20.808 on the soft tyres. Verstappen’s morning time was enough to separate the two Mercedes drivers while his afternoon running was hampered by a stoppage at turn one.
Gasly dropped one place but still remained best of the rest despite completing fewer laps than previous days due to a brake issue on the STR13.
There were yet more problems for Mclaren when a hydraulic issue brought an end to the Mclaren’s running with just 38 laps completed.
Magnussen, Hulkenberg and Sainz took positions 6-8, with Sirotkin, Perez, Ericsson, Vandoorne and Stroll rounding out the timesheets.
Final results are as follows