LONDON, England - Formula 1 turned its attention to promising young drivers with teams testing developments and tyres for 2012 at Abu Dhabi's Yas Marina track after the emirate's F1 GP.Jean-Eric Vergne, who drove a Toro Rosso during the practice sessions ahead of the GP, got to grips with Sebastian Vettel's Red Bull and set the fastest unofficial time of the day - 1min40.011. He was followed on the time sheets by compatriot Jules Bianchi, who kicked off three days of testing for Ferrari with 85 laps and a best of 1min40.960.Third was Robert Wickens, switching to Renault after taking part in a practice session for Virgin Racing, with Fabio Leimer fourth on his test debut for Sauber.DEFINITION STRETCHEDThe aim of the test is to help young drivers progress to Formula 1 while also giving teams a chance to try new ideas at a time when testing is otherwise banned. However, some teams have been accused of using the test as a money-spinner, trying out an array of well-funded youngsters eager for a chance, while others have focused more on their own technical agendas.McLaren's use of Gary Paffett (31) stretched the definition of a young driver test. McLaren team boss Martin Whitmarsh said: "I think he's still young enough to be in F1. He's someone who deserved - and still does deserve - an opportunity so I think we are very proud to be able to showcase him."Paffett was fifth-fastest, sharing the day's testing with compatriot Oliver Turvey. Max Chilton completed his first laps with Force India and rookie Valtteri Bottas tested for Williams.Sam Bird was behind the wheel of the Mercedes F1 car and will try out their new exhaust positions developed for 2012.Team principal Ross Brawn said: "We've a comprehensive programme; probably, like everybody else, we have a list that's bigger than the time available. In our case, the priority is the technical programme... we've got Nico (Rosberg) for the long term and we are not right now in the market for a young driver."Other youngsters testing were Charles Pic, linked to a race seat at Virgin/Marussia in 2012, Dani Clos (HRT), Adrian Quaife-Hobbs (Virgin), Stefano Coletti (Toro Rosso) and Rodolfo Gonzalez (Team Lotus).