Bottas and Vettel break 1m20s as Stroll crashes

Valtteri Bottas and Sebastian Vettel both got under the 1m20s barrier during pre-season testing as Lance Stroll brought a premature end to Williams' running for the second day in a row.

Having already posted a time in the 1m19s on supersoft tires, Bottas lowered the benchmark in the final hour of the morning session when using the ultrasofts, setting the pace with a 1m19.705s. The lap is notable for being 4.976s quicker than the pole position time from 2015, which is the lap the new regulations were designed to improve upon by five seconds.

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The time came during a number of quick laps for Bottas as he carried out runs on the softer compounds, following on from a productive race simulation on Tuesday afternoon. The Finn then handed over to teammate Lewis Hamilton during the lunch break as Mercedes continued with its approach of splitting running on each day.

Once again Ferrari joined Mercedes at the top of the timing screens, with Vettel second fastest on a 1:19.952. The German was on the soft tire compound for his best lap time, and allied reliability with pace as he completed 139 laps. His session ended 10 minutes early, however, with the Ferrari coming to a stop on the pit straight in an apparent fuel run-out test.

While Vettel's tally was the most laps completed by a single driver, Mercedes once again managed the most mileage as Bottas and Hamilton combined for a total of 170 laps. Hamilton was down in seventh place at the end of the day, having only run on medium or soft tires, 2.4s off his teammate's pace.

As was the case on day two, Red Bull was third quickest behind Mercedes and Ferrari as Daniel Ricciardo posted a 1:21.153. The Australian led three Renault-powered cars in the top five, with Jolyon Palmer fourth, a quarter of a second slower than the Red Bull. Palmer started the day with a low-speed spin into the gravel at Turn 3 while carrying out aero runs in cold conditions, but recovered to complete 51 laps and was encouraged by his team's progress.

The solid Renault showing was continued by Nico Hulkenberg who set the fifth-fastest time, 0.4s adrift of his teammate and just 0.033s ahead of Marcus Ericsson in the Sauber.

There were a number of red flags during the day, with the most significant stoppage being caused by 18-year-old Stroll. The Canadian lost control exiting Turn 5 on an out-lap following an off for Carlos Sainz – who had stopped in the gravel at Turn 4 – and the Williams hit the inside wall to end the team's running. It was the second day in succession that Stroll had damaged the FW40, but on this occasion he already had 98 laps to his name.

Romain Grosjean only managed limited mileage on his first day in the Haas, with 56 laps the fewest completed by a driver who carried out a full day's running. Asked if it wasn't the start he expected, Grosjean replied: "No, there were a few things that held us back in the garage so we need to work and get better in the future, but I got the first few laps in the car and learned to drive it a little bit."

There was some progress for McLaren on the third day as Fernando Alonso completed 72 laps, more than doubling the team's mileage for the week. Only the Toro Rosso and Force India – driven by Alfonso Celis – posted slower times, however, as Alonso registered a lap 2.9s off the pace despite using the ultrasoft tire.