Issues with Ferrari F1 power unit frustrate Ericsson in new Sauber

Ericsson's running was also hampered when the right-rear wheel fell off the C35 during the afternoon session at Barcelona's Circuit de Catalunya, bringing out the only red flag of the day.

The Swede still managed 55 laps overall, but it could have been more if not for the problems with the latest Ferrari power unit.

"Unfortunately not so many laps today. We had some issues all day long," he said.

"First of all there was an engine change overnight that took quite a bit longer than expected.

"Then when we got out on track there were still some issues relating to the power unit that held us back, restricting us to just doing outlaps.

"Of course it's a bit frustrating, but that's how it goes sometimes over the first couple of days in a new car."

With regard to the wheel, Ericsson added: "We don't know yet, they're investigating it, but basically it fell off when I turned into the corner."

Despite the woes, Ericsson was still reasonably impressed with what he felt from the car, echoing team-mate Felipe Nasr's positive first taste.

"I got two decent runs, we did some long runs on medium in the afternoon, so I got a small impression at least and it's fair to say we've taken a step forward in all areas," said Ericsson.

"I want to do more laps to be more specific, but definitely it feels like a stronger package.

"With regard the engine, there's definitely good potential there. The driveability has definitely improved. I also feel the braking stability has improved.

"On the aero side the car feels better in the high-speed corners, it feels stable.

"They are the two main things I felt on the limited number of laps I did, but when you drive it feels like a nicer package. It's easier to predict what it's going to do."