Lotus F1 team plans 'significant' upgrades for Spanish Grand Prix

Lotus was off the pace last season and failed to score in 2015's first two grands prix, but it has since claimed consecutive points finishes with Romain Grosjean in China and Bahrain.

"It will be an interesting weekend as many teams will bring decent upgrades to the first European race of the season and we are working on bringing a reasonably significant package in terms of bodywork upgrades ourselves," said Chester.

"There's a certain amount of anticipation to see what everyone turns up with.

"In terms of our expectations, there's nothing to say that we shouldn't have another strong race in Barcelona, just as we did in China and Bahrain."

Chester believes Lotus is currently vying with Red Bull to be the fourth-fastest team on pure pace.

"Certainly, it's pretty competitive in the midfield and fighting to be at the head of the chasing pack," he said.

"Mercedes are still the team to beat this season although Ferrari is giving them a chase at the moment.

"There is a fairly big gap to Williams who are followed by Red Bull and us - there is a smaller gap there and we can race them."

MALDONADO HAS BEEN A 'VICTIM'

Pastor Maldonado returns to the track where he claimed his first - and as yet only - F1 victory in 2012 having not scored a point in the first four races.

The Venezuelan was caught up in first-lap incidents in Australia and Malaysia and was taken out by Jenson Button in China, although he also made costly mistakes of his own in both that race and the following Bahrain GP.

Lotus deputy team principal Federico Gastaldi backed Maldonado and claimed he has been mainly a "victim" of other drivers' mistakes this year.

"We're still waiting for those first 2015 points with Pastor and no one wants them more than the man himself," said Gastaldi.

"Pastor is driving really well and has been the victim of other drivers' mistakes rather too much this year.

"We know he likes the E23 and can get it to deliver very good pace.

"Pastor enjoyed great success in Barcelona a few years ago so hopefully that is a good omen for him."