Kevin Magnussen says he leaves the first test feeling better than expected after being able to run the Renault Sport F1 car until it literally ran out of fuel in the final hour of the last session.

The Danish driver has enjoyed a marathon amount of running time during his two days in the RS16 notching up 264 laps in total with a best time of 1m 25.263s on the soft Pirelli tyres to end the last day fourth on the timesheet.

Magnussen produced the highest number of laps behind the two Mercedes drivers and says being able to run the Renault until it gave up, when he ran out of fuel at the end of the afternoon session, came as a welcomed surprise.

"I would say when I started the week, seeing the problems on the first two days it was a bit concerning," Magnussen said "I was worrying a bit if I would get as many laps as I wanted but I've certainly got that now. It's been a good couple of days I think. The main thing is just that I've got so many laps, it's been perfect in terms of just getting back in to it and just pounding laps, it has been really good."

Magnussen had been watching on anxiously as his new team-mate Jolyon Palmer was only able to muster 79 laps over his two days in the car due to mechanical issues and needed an engine change on Tuesday afternoon.

With a bolstered bank of laps, data and information, Magnussen is confident he and Palmer can benefit from it having established a solid baseline set-up to build upon at the second pre-season test next week while he is also keen to get higher downforce levels from the aerodynamics package.

"It's a good baseline. It's nice to drive, lacking downforce and power but it's important to have a good baseline," he said. "We're not trying to chase a different balance or different characteristic, we just need to add downforce. It's a difficult job to add downforce without changing the characteristics of the car, so that's what we need to work on."

"We have only had four days now so we are still very much learning about the car. Obviously aero is very dominant in F1 and I think this car has very stable aero, it doesn't mess up the aero when you go through mid-corner or when you go over the kerbs. It seems quite driver-friendly, so we need to keep that when we try to put downforce on the car."