F1 qualifying gains are vital in rest of 2015 - Marcus Ericsson

The Swede is currently down 6-3 to team-mate Felipe Nasr in head-to-head qualifying and hasn't made it into Q3 since the Chinese Grand Prix in April.

Nasr managed eighth on the grid in Austria last month, and while Ericsson got the upper-hand as both Saubers struggled at Silverstone, he knows it's where work is required.

"For me it's quite clear that I need to step up my game in qualifying," he said.

"That's where I've been hurting the most, especially compared to my team-mate.

"The problem with that is that it sets up the whole race when you are second in the team in qualifying and you don't have priority on strategy, it's always going to make life more difficult.

"The car is well balanced and nice to drive, but sometimes you need to find ways to make it more suitable for the driving style you like to drive, to be able to extract more out of it.

"For me, I need to find a way to be able to get more of an edge in qualifying."

While Ericsson notes that Sauber's lack of upgrades during the first half of the season has not been "fun", he's optimistic that engine and aero updates due at Spa and Singapore will arrest the slide.

"We have been struggling a bit to keep up with the competition lately, not bringing so many upgrades as other people have done," he said.

"In a way it's not been a surprise for us because we knew that the big upgrades were going to come in the second half of the year and that's the philosophy that the team chose from the beginning of the year.

"Of course it's not as fun to be not as competitive as we were in the beginning of the year, but we still have to maximise what we have, and hope for the second half of the year to be back in good form."