Valtteri Bottas unsurprisingly produced the fastest lap on day one of the 'alternative' Young Driver test at Silverstone, as Williams faced off against backmarkers Marussia and HRT.
The Finn, sitting out racing this year to focus on his reserve role with the Grove team, has been a regular in Friday morning free practice at grands prix, and made his familiarity with Williams' FW34 count as he posted 1min 31.436secs on the softer Pirelli tyre.
"It's been a busy day, completing 120 laps without any problems," Bottas reported, "We had a little rain towards the end but tested everything we wanted to on mixed fuel levels.
"It's been a really useful day for both me and the team. The shorter runs are good fun, especially on this track, but I was particularly looking forward to the longer runs. It was really useful to gather some information on how the tyres behave over the various runs and I feel that I am continuing to improve as a driver.
Bottas' margin over the rest of the field was a massive five seconds, as both Marussia and HRT chose to field inexperienced pilots. The former's Max Chilton posted the second-best mark, at 1min 36.558secs, but completed just a quarter of the laps enjoyed by Bottas as the Banbury team opted to split track time between the Briton and GP2 team-mate and rival Rio Haryanto.
The Indonesian covered an other 19 tours, slotting into third place between Chilton and F1 debutant Ma Qing Hua, who completed 82 laps in the HRT. All four drivers enjoyed the dry running on hand to get more mileage under their belts, with the only weather-related interruption coming as teams were beginning to wrap up their day's activities.
Despite HRT's claims that its pilot was the first Chinese national to drive an F1 car - that was, in fact, Dutch-born Ho Pin Tung when he ran with Williams in late 2003 - Hua started the day with short runs to adapt to the car on both tyre options, then switched to qualifying simulations, and a combination of starts and pit-stops, before culminating in a long distance run at the end of the day.
"I think we did a good job and everything went according to plan, with good weather too," he commented, "By being here during the grand prix, I learned a lot from my team-mates and also to work as a team, as it is very important to give the right information to the engineers in order to optimise the performance of the car."
The test concludes on Friday with Williams and Marussia using the shorter International Circuit with the same drivers as day one. HRT, having completed its programme, is heading back to Madrid overnight to begin preparations for the forthcoming German Grand Prix.
Leading times - Silverstone Young Driver test (day one):
1. Valtteri Bottas
Williams 1min 31.436secs
2. Max Chilton
Marussia 1min 36.558secs
3. Rio Haryanto
Marussia 1min 37.404secs
4. Ma Qing Hua
HRT 1min 37.829secs
Times courtesy of F1.com