Robert Kubica says a priority for Williams ahead of the 2018 Formula 1 world championship will be to unlock a comfortable feeling from the FW41 for Lance Stroll and Sergey Sirotkin after a challenging pre-season testing.

As part of his third and reserve driver role at Williams, Kubica was drafted in to provide an experienced head in the early development of the team’s new F1 challenger, the FW41, alongside rookie Sirotkin and Stroll.

On the final day of pre-season testing action, Kubica “sacrificed” his opportunity to test the car in order to give Stroll the last chance to drive the FW41 ahead of the 2018 season opener.

While Kubica refused to speculate on the weak points of the 2018 Williams F1 car, the Polish driver accepted the team was struggling to deliver a confident feeling from the car for its race drivers.

“From my point of view and the goals we had I think I had a quite clear view of where we have to do some work on the feeling of the car,” Kubica said. “I think in order to maximise potential it’s a race drivers job to optimise it and to maximise it.

“It’s the early stages of the car, the weather did not help us in the first week and this week was better so we started working into the details probably every team is doing.

“The first week is more of getting the data and trying to see if all the numbers are on target and matching the teams’ expectations, and the final days are more about fine tuning the car and trying to find the optimal way of setting it up.”

But Kubica has faith in Williams to resolve the situation with the weather conditions in Melbourne being more representative compared to the cold temperatures at pre-season testing in Spain.

“In Australia the track is different, the conditions will be different, so for sure the first few races we will be trying to also understand how our car is behaving in different circumstances, different conditions and in different tracks,” he said. “I think it’s very early to say we did struggle with the balance.

“I think we are in a delicate situation depending on the tyre temperatures and the weather - this makes us very sensitive, so that’s why we already addressed the problem and we try to do some different solutions.”