Red Bull’s Daniel Ricciardo set the pace at the mid-point of Wednesday’s test session in Spain, clocking a new unofficial track record as the times tumbled.
Reigning World Champion Lewis Hamilton had initially posted blistering speed on Pirelli’s Unmarked tyres, dipping beneath the Circuit de Barcelona-Catalunya's track record, set by Felipe Massa in 2008.
However, Hamilton’s lap was disallowed after it was deemed that he cut the chicane, though the Briton soon posted a 1:18.400 on Ultrasofts, as he edged closer to the record.
Ricciardo overhauled Hamilton to go fastest of all, registering a 1:18.357, on Hypersofts, bringing him just 0.018s slower than Massa’s record, which was set at a 2008 test on slicks, during an era in which grooved tyres were mandatory.
Ricciardo, though, soon destroyed Massa’s previous best, logging a time of 1:18.047, leaving him 0.353s clear of Hamilton, who marginally completed the most mileage, logging 90 laps compared to Ricciardo's 89.
Ferrari’s Sebastian Vettel was third, on Soft tyres, while Fernando Alonso used Hypersofts to go fourth for McLaren, before encountering another setback.
Alonso had posted promising mileage in the early hours but halted at Turn 7 shortly after 11:00 due to a small oil leak, which has necessitated an engine change.
McLaren does not expect the MCL33 to be repaired before 15:00 local time, costing the team more running, after enduring a disrupted programme on Tuesday, when Stoffel Vandoorne stopped three times.
Carlos Sainz Jr. was fifth for Renault, in front of Haas’ Romain Grosjean and Williams’ Lance Stroll, as Force India’s Esteban Ocon placed eighth, the quartet all adding valuable mileage to their 2018 challengers.
Brendon Hartley triggered a brief red-flag period when he spun at Turn 12, though was able to recover to the pits, as Charles Leclerc brought up the rear, 2.8s slower than Ricciardo.
Running will continue through to 18:00 local time.
| Pos | Driver | Team | Time | Gap | Tyre |
| 1 | Daniel Ricciardo | Red Bull | 1:18.047 |  |
|
| 2 | Lewis Hamilton | Mercedes | 1:18.400 | 0.353 | |
| 3 | Sebastian Vettel | Ferrari | 1:19.541 | 1.494 |  |
| 4 | Fernando Alonso | McLaren | 1:19.856 | 1.809 | |
| 5 | Carlos Sainz | Renault | 1:20.042 | 1.995 |  |
| 6 | Romain Grosjean | Haas | 1:20.237 | 2.190 | |
| 7 | Lance Stroll | Williams | 1:20.349 | 2.302 | |
| 8 | Esteban Ocon | Force India | 1:20.805 | 2.758 | |
| 9 | Brendon Hartley | Toro Rosso | 1:20.834 | 2.787 | |
| 10 | Charles Leclerc | Sauber | 1:21.110 | 3.063 |  |
