Despite a laid-back approach to most of the day’s running at Silverstone Circuit, Kevin Magnussen ended the first day of the F1 Young Driver Test at the top of the timesheets following a blistering run set on the Pirelli medium compound only 20 minutes before the end of the session.

For much of the afternoon it had looked as though Antonio Felix da Costa would claim top honours for Red Bull. The Portuguese racer spent the morning trading fastest laps with James Calado before delivering more of the same in the afternoon, this time duelling with experienced racer Paul di Resta.

At the end of the morning’s running it was Calado who topped the timesheets for Force India with a 1m33.986s lap before handing the car over to race driver di Resta for the afternoon. Calado will be back behind the wheel of the VJM06 on either Thursday or Friday.

Also limited to a morning’s running was Marussia’s Tio Ellinas, currently leading the GP3 championship. After 36 laps behind the wheel of the MR02, having set a fastest lap of 1m36.767s, the Cypriot racer handed over the controls to Max Chilton, so that the team’s race driver could evaluate the new Pirelli tyres. But Chilton was affected by an ECU problem that kept the Briton in the garage for much of the session.

Late in the afternoon the Caterham – driven by Alexander Rossi – suffered hydraulics failure, costing the American racer his best chance at a quick lap. Despite the issue, Rossi was able to complete 69 laps before calling it a day.

Daniel Juncadella lost out on significant track time in the morning, completing only five laps for Williams. But the Spanish racer made up for it with a long afternoon stint that saw Juncadella end the day fifth on the timesheets, with 55 laps under his belt.

Another driver to see reduced running on Wednesday morning was Robin Frijns, who did not leave the garage in his Sauber until the pitlane had been open for two hours. Despite the slow start, the Dutch driver gave a strong showing in the morning session, running in third on the timesheets. By the end of the afternoon, however, Frijns had slipped down to seventh with a fastest lap of 1m34.236s.

Also testing today were Johnny Cecotto, who managed sixth for Toro Rosso after finding some late afternoon pace; Nicolas Prost, who was eighth for Lotus with a 1m34.810s; and Davide Rigon, who was hot on Prost’s heels with a 1m34.874s lap for Ferrari.

Testing resumes at 9am (BST) on Thursday 18 July.

YDT times (unofficial)

1. Kevin Magnussen (McLaren) 1m33.602s [100 laps]
2. Paul di Resta (Force India) 1m33.774s [58 laps]
3. Antonio Felix da Costa (Red Bull) 1m33.821s [82 laps]
4. James Calado (Force India) 1m33.986s [27 laps]
5. Daniel Juncadella (Williams) 1m34.098s [55 laps]
6. Johnny Cecotto (Toro Rosso) 1m34.193s [75 laps]
7. Robin Frijns (Sauber) 1m34.236s [72 laps]
8. Nicolas Prost (Lotus) 1m34.810s [72 laps]
9. Davide Rigon (Ferrari) 1m34.874s [76 laps]
10. Alexander Rossi (Caterham) 1m35.651s [69 laps]
11. Tio Ellinas (Marussia) 1m36.676s [36 laps]
12. Max Chilton (Marussia) 1m38.347s [27 laps]