Giancarlo Fisichella and Franck Montagny kicked off Vijay Mallya-owned Force India Formula One Team's testing at the Circuit de Jerez in Spain on Wednesday.
The duo made their debut runs in the team's burgundy and white challengers working through a schedule of chassis development.
The day was marred by several red flags and spins from both the drivers raising questions about the stability of the car and the work needed to start the season with a stable machine.
"Today was a slightly frustrating day of testing, with many red flags and a couple of minor mechanical issues on the cars, which meant we did not get through our whole programme," said Mike Gascoyne, chief technical officer, in a press release.
Fisichella and Montagny covered more than 500 km on the circuit with Renault driver finishing a shade quicker than his counterpart with a lap of 1:21.424.
On his first day in an F1 car after the last race in Brazil, Fisichella said he had a problem with the hydraulic pressure and when he tried out the 'slick' tyres there was another problem so the team did not get a proper idea of how the tyres will work.
"It's my first day back in the car, nearly two months after the last race in Brazil, plus my first with another car and new engine - and, of course, without the electronics," Fisichella noted after posting a best of 1 min 21.424secs in the course of 53 laps, "Considering this, I am quite happy about how the day went.
"We did have a couple of issues, so I didn't run as much as I would have liked. With new tyres, I had a problem with the hydraulic pressure and, when I tried out the slick tyres, there was a problem on the diff, so we didn't get a proper idea of how the tyres will work. All the same, I do think it's been a positive day and a good basis for tomorrow."
Force India seems to be keen on backing Fisichella as their lead driver as he will drive for a second day of testing which will continue on Thursday and will be joined by Christian Klien.