With the outfit being forced to pull out of last week's test at Barcelona because of a front suspension issue, and having plans to make up for that time with a run at Silverstone next week now scuppered, the pressure is on to ensure it has a perfect next few days of running.

"Obviously we want to have the same reliability that we showed in Jerez and do the maximum mileage we can," Boullier told AUTOSPORT ahead of its revised E20 taking to the track at Barcelona on Thursday.

"We will never catch back these four days we lost, but we need to make the best of these four days coming up in front of us to make sure that we do well."

Boullier says there is some encouragement from the fact that Lotus showed so well in the first test in Jerez, but he knows that what really matters is how its updated car compares to the opposition.

"In Jerez the reliability was good and the pace was good, but it means nothing too much because it was the first test," he said. "We have a lot of upgrades coming for the car like the others, for the test and for the first race, so let's see now.

"But definitely the basis was good, and the drivers were happy with the handling of the car. The car had a good balance so it was a good start."

Boullier has denied talk that the front suspension issue was the result of the outfit having tried to push too hard to take weight off its design - a theory backed up by the fact that the revised suspension components are 1kg heavier.

"No, no, no, it was nothing like this," he explained. "There was a small deviation between design simulation and one component we had on the car, and obviously with the fitting of this mount on the front – we were not happy with the results. We decided for many reasons to focus on redesigning it and redoing it, and to get rid of this."

Boullier also said his team accepted the decision of the FIA not to allow his outfit to test for an extra day next week – because the governing body believed it would be a breach of rules that prevent running in the week 'preceding' the first event.

"I think we had a different interpretation [of the rules]," explained Boullier. "The teams agreed that we could go for another day next week, but the FIA came back to us and said we cannot – so that is the end of the story."

Autosport.com