The Dinnington-based team has taken a significant step forward this season, in part thanks to the use of the Mercedes engine, but it is still struggling to escape the last positions in most races.

"There is no doubt that this year's car is a massive step on last year's. But we are still nowhere near quick enough," Ryan told Reuters in an interview.

"This year we're definitely able to be competitive with some of the cars around us and the performance gap we had to find to do that was massive. But we need the same improvement again.

"It's not one area in particular, it's everywhere," he added.

Midfield target

Ryan concedes Manor may need up to five years to start fighting in the midfield.

"We clearly desire to be a really solid midfield team, but we also know that's a long game.

"We are not going to get there this year or next year. It might take four or five years," he added.

The New Zealander, whose team's best result this year has been a 13th place in Bahrain, said beating Sauber is its main goal at the moment.

The Swiss squad has scored a couple of 12th-place finishes, and Ryan says Manor would be disappointed not to finish in the top 10 in the standings.

"The way we look at it is they are just another team we've got to try and beat. It just happens to be Sauber next door to us and to some people they are the obvious target.

"I think we'd be very disappointed if we didn't finish 10th, that's for sure."