Romain Grosjean has refused to get carried away by the performance of Lotus in Barcelona this week, insisting that fourth place in the constructors' championship is the aim for the year ahead.

The French driver led the way on the opening two days of action in Catalunya as Lotus looked to bounce back from the chassis issues that forced it to curtail its running during the second test of the winter after just seven laps.

However, despite his encouraging performance this week, Grosjean insisted that the aim for the year ahead was to finish fourth as part of the gradual move towards fighting for the title.

"It seems to be," he told ESPNF1 when asked if Ferrari and Mercedes will be the main rivals to the Enstone-based team this season, "but then maybe Force India is strong as well. We don't know about Toro Rosso, it's always tough to know where you are.

"Last year we finished fifth in the championship, this year we want to finish fourth so we'll have to beat one of the guys who were in front ... the target is for 2015 to be world champions; you have to go step-by-step and not try to jump three steps in a row."