Charles Pic declared himself 'happy' after making his Formula 1 return during the second in-season test in Spain.
Lotus reserve driver Pic tested the E22 at the Circuit de Catalunya-Barcelona on Tuesday and completed 70 laps on his way to setting the second fastest time.
It was the first time that Pic had sampled a Formula 1 car since he departed Caterham after the Brazilian Grand Prix at the end of 2013.
"The programme was quite big on the morning [but] because of the weather we had to make it a big smaller," he said. "The morning was not ideal as it was raining so we were not able to start our programme. After it got better during the day, for myself it was a bit longer without driving since Brazil so I was happy to be back in. Overall I think it was a very good day for the team and for me."
Pic admitted that he took a while to get used to a 2014 spec Formula 1 car.
"It took me a few runs as there’s lots of change compared to last year – the power unit is different and the feeling you have on the pick-up and the throttle transition is different so you need some time to get used to it," he said. "But it was fine. No problems, a good day."
Pic said that the focus on optimising the power unit was crucial, but the demise of KERS in favour of an automatic ERS aided the role of the driver.
"A bit more [difficult] on the power unit as you have to take car when you charge, when you don’t charge, when you want to deliver the energy and take and optimise all these parts," he said. "Last year we didn’t do this. This year you don’t have KERS – you have it but it’s automatic."
Regular driver Pastor Maldonado will resume testing duties on Wednesday.