A buoyant Jonny Reid has overcome early nerves to be among the frontrunners on day one of the two-day testing session at Silverstone in England , the first hit-out ahead of season three in the A1GP World Cup of Motorsport.

Reid's best lap of 1:11:025 was the 4th fastest time in the morning session and just 0.01 of a second off his quickest time in testing at the same circuit last year.

The 23-year-old was less than half a second behind the pace-setting French, season one champions, and was "chuffed" with his effort considering he hasn't raced competitively since April.

"The time I spent out of the car was longer than I would've liked, so it's pleasing to be up there with guys who have been driving all year," Reid said.

"It felt like my first day at school, but the early nerves have given way to a big smile from ear to ear.

"It's a huge buzz to be back in Black Beauty, but you forget how powerful the car is and how she can brake on a dime. At the start I was braking so early out there, I had to remind myself I wasn't in my Audi A3!"

Reid completed 43 laps before handing over the reigns to 17-year-old Brendon Hartley for his first stint in an A1GP car.

Hartley also completed 43 laps and, despite running on old tyres, posted the 11th fastest time of the afternoon session, when most teams set quicker times.

"It was a good experience and I learnt a lot," Hartley said. "It was important to gain knowledge for the team and I was determined not to do anything stupid.

"Once I got more confident with the car I started throwing it around a bit and having fun.

"The time was quite competitive given most of the drivers ahead of me were on new tyres and I'd like to think I can push into the top five once we get new rubber on tomorrow."

Hartley is expected to drive in the three and a half hour morning session before Reid polishes off the two-day hit-out in the afternoon.

A second two-day test session at Silverstone will be held on 18-19 September and will be the last chance for teams to improve set-ups and finalise driver choices before the opening round at Zandvoort on 30 September.