MONTMELO, Spain -- Red Bull's Daniel Ricciardo topped the opening day of Formula One testing as the 2018 pre-season got underway at the Circuit de Catalunya.
Ricciardo's lap -- a 1:20.179 -- was 1.6s faster than the best time on the first day of testing last year and put the Red Bull 0.170s clear of Valtteri Bottas' Mercedes in second place. Ferrari's Kimi Raikkonen set the third fastest time -- 0.327s off Ricciardo -- ahead of Nico Hulkenberg, who showed promising pace in the Renault just 0.041s off Raikkonen's best effort. The Red Bull, Mercedes and Renault were all on Pirelli's medium compound tyre, the Ferrari was on the faster but less durable soft compound.
The majority of the fastest times were set in the morning before a cold front and heavy cloud settled over the circuit in the afternoon. Track temperatures dropped to single figures and the air temperature was only just nudging six degrees Centigrade in the final two hours of running. Combined with fine drizzle, the conditions worsened significantly in the final hour of the session and most teams curtailed their run plans in the belief they would learn little and risk a lot.
As a result, reigning world champion Lewis Hamilton was limited to just 25 laps in the afternoon compared to the 58 completed by teammate Bottas in the morning. Hamilton had flown in from Milan in the morning after attending a fashion event with team partner Tommy Hilfiger yesterday evening, but given the conditions he may have preferred to remain in Italy. He will continue to split testing duties with Bottas each day for the rest of the week, although conditions are only expected to get worse over the coming days.
Now a Renault engine customer, McLaren was hoping to hit the ground running this year after three seasons of pre-season struggles with former engine partner Honda. But those plans were dashed on just the seventh lap of Fernando Alonso's debut in the bright orange MCL33 when the right-rear wheel worked loose of its fastening and spat the McLaren into the gravel at the final corner. The team spent three hours looking into the the failure before it was satisfied that Alonso could return to the track for another 41 laps without issue.
Pushed on the reasons for the failure, McLaren racing director Eric Boullier said: "The wheelnut issue was just a wheelnut issue, so I'm not going to comment. You know what it is.
"You lose a wheelnut and you lose a wheel and that's it.
"Obviously it cost us track time, which is the only downside today, but we are now back and running our programme. Maybe we are going to compress it to jump on the most important items that we need to run today."
Alonso finished the session fifth fastest but it later emerged he had cut the final chicane on his fastest lap and he was dropped to seventh. That moved Carlos Sainz, who took over Renault testing duties in the afternoon, to fifth and Hamilton up to sixth.
After three years of limited mileage during pre-season testing since its F1 return in 2015, engine supplier Honda enjoyed a solid day with its new partner Toro Rosso. The team completed 93 laps with Brendon Hartley at the wheel and set the eighth fastest time by the end of the session. That lap count was only beaten by Red Bull on 105 laps, after Ricciardo opted to continue running up until the chequered flag despite the wet conditions in the final hour.
Lance Stroll split Williams' test day with new teammate Sergey Sirotkin and the pair completed 68 laps between them. Stroll finished the session ahead of Romain Grosjean in the Haas, Marcus Ericsson in the Sauber and Force India development driver Nikita Mazepin, who completed 22 laps before spinning off in the gravel at Turn 4. The Force India failed to return to the track for the rest of the day, suggesting Mazepin may have caused damage that requires new parts to be flown in before the car can run again.
Sirotkin finished at the bottom of the timesheets, 23.9s off Ricciardo's best time, but was mainly completing installation laps through the pits during the worst of the conditions.
1. Daniel Ricciardo - Red Bull - 1:20.179 - 102 laps
2. Valtteri Bottas - Mercedes - 1:20.349 - 58 laps
3. Kimi Raikkonen - Ferrari - 1:20.506 - 80 laps
4. Nico Hulkenberg - Renault - 1:20.547 - 73 laps (AM)
5. Carlos Sainz - Renault - 1:22.168 - 26 laps (PM)
6. Lewis Hamilton - Mercedes - 1:22.327 (PM)
7. Fernando Alonso - McLaren - 1:22.534 - 48 laps
8. Brendon Hartley - Toro Rosso - 1:22.371 - 93 laps
9. Lance Stroll - Williams - 1:22.452 - 46 laps (AM)
10. Romain Grosjean - Haas - 1:22.578 - 55 laps
11. Marcus Ericsson - Sauber - 1:23.408 - 63 laps
12. Nikita Mazepin - Force India - 1:25.628 - 22 laps
13. Sergey Sirotkin - Williams - 1:44.148 - 25 laps (PM)