Daniel Ricciardo posted the quickest time on the second day of F1's Young Driver Test at Silverstone, although it was his morning run for Toro Rosso that saw him emerge with the fastest time seen so far this week.
The Australian was splitting his running between his current team and Red Bull, with his afternoon programme being widely seen as an opportunity for the defending champions to evaluate him as a possible replacement for sportscar-bound Mark Webber.
Ricciardo's fastest time in the STR8 saw him become the first – and so far only – driver to break the 1min 33secs as he worked through a Pirelli tyre programme, and it was enough to beat young Spaniard Carlos Sainz Jr by just 0.044secs.
Sainz, son of former WRC title winner Carlos Sr, produced a highly impressive performance after taking over from Ricciardo for the afternoon session and came close to ending his first day in F1 machinery with the best time.
Ricciardo was then third fastest with the time he posted during the afternoon having switched to Red Bull's RB9, although his time in the car wasn't without drama after he suffered a spin into the gravel with just seven laps on the board.
Luckily the car wasn't damaged and he returned to the track to complete 59 laps for the defending champion which, added to his morning laps in the Toro Rosso, made him the busiest man on track.
“It was good today but very busy, so it's still a bit of a blur,” Ricciardo said. “I did quite a few laps this afternoon, so I'm happy with that. I had a small off but otherwise it was a trouble-free day. The off was my mistake, I just lost the rear on the entry. It was a good opportunity to get behind the wheel and experience two different beasts today. In terms of the inevitable speculation, I think this test is something for Red Bull to look at, but there's still the rest of the season with Toro Rosso to do, so I'll switch my focus back to that and won't get too caught up in any rumours.”
Davide Valsecchi was fourth fastest for Lotus as he sampled the E21 for the first time since his half-day on track at Barcelona at the start of the year, while British pair Oliver Turvey and James Calado rounded out the top six for McLaren and Force India respectively; the latter again running in the morning only to gain further experience of F1 machinery.
Antonio Felix da Costa completed his programme with Red Bull in the morning and was seventh quickest, with Davide Rigon, Pastor Maldonado and Nico Hulkenberg completing the top ten.