MONTMELO, Spain -- Nico Hulkenberg finished the first test of 2019 at the top of the timesheets, but it is Ferrari who can leave with bragging rights after another impressive day at the Circuit de Catalunya.
Hulkenberg's time led the way at the end of the session. The Renault driver set a 1:17.393 on the softest and quickest tyre, known for preseason as the C5 compound, in the afternoon. That put him 0.3s up on Toro Rosso's Alexander Albon, 0.4s on Renault teammate Daniel Ricciardo (who drove the yellow and black car in the morning) and 0.5s on Mercedes' Valtteri Bottas, who all set times on the same tyre before lunch.
But in terms of trying to understand the benchmark by which to judge the rest (in the context of Thursday, at least), the key man from the session was Charles Leclerc. The Ferrari driver set a 1:18.046 on the middle compound in Pirelli's range of five, otherwise known as the C3, but that becomes a 1:16.800 once corrected to a C5 estimate according to the differences in performance Pirelli estimates between the various tyres. Reigning world champion Lewis Hamilton went quicker than Leclerc on the outright time, setting a 1:17.977, but set his on the C4 -- when his time is 'tyre corrected', he comes in at 1:17:300, 0.5s behind Leclerc.
Exact fuel loads are one of the key unknowns at this stage of testing, so it is always risky to take a time from the fourth day of an eight-day test schedule and treat it as gospel. But given that this was the first day Mercedes turned its attention toward performance, it provided the first meaningful comparison of any sort between the two teams. Leclerc also continued Ferrari's impressive mileage, accumulating 138 laps over the day, while Bottas and Hamilton combined either side of lunch for 115 of their own.
By contrast, Red Bull did not complete a lap that could be considered comparable to the others, with Pierre Gasly's 1:18.720 a full 0.7s down on Leclerc. Like Leclerc, Gasly set his time on the C3 tyre, but Red Bull said it was focusing more on longer and higher-fuelled runs with its new Honda power unit than on outright performance at this stage.
"Overall, the overall feeling for the car is really good even if it doesn't show it on the lap times," Gasly said. "We are testing and we know what we're doing, so I'm pretty happy, and there a lot more tests coming next week."
When asked about Red Bull's new engine, he said: "I think it's really good. Looking at Toro Rosso, they have been really fast with the Honda engine, and we are happy with it, as well. There is still some work to be done, but I think Honda did a really good job over the winter. Still a few things to come next week, but the first four days have been really good."
Gasly's 146 laps were second only to Antonio Giovinazzi's 154 for Alfa Romeo. The only blot on Giovinazzi's impressive stint in the car were two stoppages in quick succession at the very end of the day. The new Alfa Romeo has gained a lot of admirers in the paddock this week and will be one of the cars to keep an eye on next week as the focus continues to shift away from mileage and toward unlocking outright performance.
Elsewhere, it was a productive day for a number of other teams and drivers. McLaren's Lando Norris recovered from a trip to the gravel trap in the opening minutes of the session -- prompting the first red flag of the day -- to record 132 laps. After a few days punctuated by delays, Haas had a more productive day, with Romain Grosjean and Kevin Magnussen combining for 130 laps. The American team was targeting a clean day having suffered three on-track stoppages on Wednesday.
Racing Point is at the lower end of the total mileage scale for the week and added 72 laps to its name with Lance Stroll. The Canadian driver's quickest time was 2.3s off Hulkenberg's benchmark but came on the C2 tyre, the second hardest in Pirelli's range. Racing Point -- formerly Force India -- is known for making slow starts to testing and will hope to unlock more from its car next week.
Williams completed its first full day of preseason testing but will have hoped for more laps. Robert Kubica completed 48 in the morning, but rookie driver George Russell was only able to add 17 after the team opted for a long lunch to work on the car. That means the Grove team finishes Week 1 with fewer than 100 laps to its name.
The second test will begin at the same circuit on Tuesday and run for four days.
Times at close:
1. Hulkenberg, Renault, 1:17.393, 24 laps (C5)
2. Albon, Toro Rosso, 1:17.637, 136 laps (C5)
3. Ricciardo, Renault, 1:17.785, 34 laps (C5)
4. Bottas, Mercedes, 1:17.857, 57 laps (C5)
5. Hamilton, Mercedes, 1:17.977, 58 laps (C4)
6. Leclerc, Ferrari, 1:18.046, 138 laps (C3)
7. Norris, McLaren, 1:18.431, 132 laps (C4)
8. Giovinazzi, Sauber, 1:18.511, 154 laps (C3)
9. Grosjean, Haas, 1:18.563, 64 laps (C3)
10. Magnussen, Haas, 1:18.720, 66 laps (C3)
11. Gasly, Red Bull, 1:18.780, 146 laps (C3)
12. Stroll, Racing Point, 1:19.664, 72 laps (C2)
13. Russell, Williams, 1:20.997, 17 laps (C3)
14. Kubica, Williams, 1:21.542, 48 laps (C2)