Hungary F1 test: Kubica fourth fastest as Norris challenges Vettel

Kubica, driving a contemporary F1 car for the first time since his career was interrupted by a rallying crash in 2011, clocked up an impressive 142 laps, across 20 stints, with a best time of 1m18.572s, 1.448s adrift of Vettel.

Having ended the morning session seventh quickest, the 32-year-old Pole started the afternoon with a series of shorter runs, many of which involved pitting in between to practice hitting his marks in the pit box.

The majority of the runs were on supersoft tyres, but he did three on the ultrasoft at the end of the day, enabling him to improve his position on the timesheets to fourth.

His lap count meant he completed the equivalent of just over two Hungarian Grand Prix race distances during the eight-hour session.

Kubica's form on Wednesday at the Hungaroring is considered to be crucial in determining whether he can complete a remarkable return to F1 next season.

Given the test takes place just days after the Hungarian Grand Prix and in similar conditions, Renault had the chance for a like-for-like comparison against the benchmarks set at the weekend by Nico Hulkenberg and Jolyon Palmer.

"It was a fantastic feeling for me to be here today in the RS17 and also it was amazing to see so many fans come to see me out on track, so thank you to all of them," said Kubica.

"It has been an incredible journey to this point, where I have answered many questions to myself. The car is certainly wider than before. I was able to work through the team's programme methodically and I think we made good progress.

"After today, it's too early to say what the next step might be. For now, I owe a big thanks to everyone at Renault for making this test happen."

Vettel's leading time set in the morning, on a day when he only completed two hours of running before handing the Ferrari over to teammate Kimi Raikkonen, remained unchallenged in the afternoon.

Lando Norris, who is driving for McLaren in Hungary as part of his prize for winning the 2016 McLaren Autosport BRDC Award, was the Ferrari's closest challenger, though his best lap was on ultrasofts one step softer than Vettel.

Raikkonen was third quickest, with Carlos Sainz fifth, a quarter of second ahead of Toro Rosso teammate Daniil Kvyat, who took over driving duties in the afternoon.

Mercedes DTM frontrunner Lucas Auer, who only drove in the morning, was fifth, with Russian Formula 3 driver Mazepin driving the Force India after lunch and ending up ninth.

George Russell, who ran the Halo cockpit protection device briefly on Wednesday, completed his second successive day of testing with Mercedes in eighth, with Red Bull's Pierre Gasly 10th.

Formula 2 frontrunner Luca Ghiotto clocked up a staggering 160 laps - more than any other driver - on what was his first day of testing a F1 car. He was 11th quickest.

Haas development driver Santino Ferrucci and Honda F1 junior Nobuharu Matsushita ended up 12th and 13th respectively.

The session ended five minutes early following a third red flag in around 20 minutes.

Wednesday results