The newest recruit to the Cooper Tires British Formula 3 grid, flying Finn Valtteri Bottas, wasted no time in getting down to business today in official testing on the Donington Park Grand Prix circuit.

The 21-year-old, recently crowned GP3 champion, handled with aplomb his elevation to the ranks of Europe’s most competitive single-seater series, hurling his Mercedes-powered Double R Racing machine to the top of the timesheets in the day’s opening session, six-hundredths ahead of the Carlin-run Dallara-Volkswagen of Kevin Magnussen.

Bottas ended the session with an off into one of Donington’s gravel traps but bounced back in session two to go quicker still; not quick enough, however, to end the day on top of the pile: that honour fell to Carlin’s Jazeman Jaafar.

Jaafar’s best lap of the day came towards the end of session two, the Malaysian repeating his Rockingham testing form to go top with a 1m 22.846s lap, three-hundredths ahead of his Carlin team-mate Rupert Svendsen-Cook. It was a Carlin 1-2-3-4-5, in fact, with Magnussen, Jack Harvey and newly crowned British Formula 3 Champion Felipe Nasr next up.

Fortec’s Will Buller was sixth to beat Bottas to the honour of leading Mercedes runner by a three-tenth margin.

Bottas will race for Double R alongside regular pilots Pipo Derani and Scott Pye in this weekend’s Donington races and also at the Silverstone finale next month. It’s not Valtteri’s first taste of British F3 - he placed third in one of the 2009 Spa-Francorchamps rounds for the ART Grand Prix team. He’s using the end of season races to get reacclimatised to the superior power and aerodynamics of a Formula 3 chassis ahead of the 20 November Macau Grand Prix.

Official qualifying and the 30-minute 25th round of the championship are scheduled for Saturday 24 September at Donington Park, with two further races, of 20 and 40 minutes duration respectively, on Sunday.

British Formula 3 enjoys the headlining support of Cooper Tires and is additionally backed by Sunoco Racing Fuels, Anglo American Oil Company and OAMPS.