Lotus supremo Gerard Lopez believes that his team have "learned" from a difficult 2014 and is hoping for a much-improved performance next season.
The Enstone-based team lost Kimi Raikkonen and design guru James Allison, who both joined Ferrari last winter, while Eric Boullier jumped ship to McLaren.
However, Lopez has claimed that those departures may not lead to a long-term decline and has suggested that using Mercedes engines could boost results.
He told Auto Hebdo: "Our new Mercedes engine will make the difference, although Renault was not solely to blame for the disastrous 2014 season.
"There was so much written about good people leaving, but what is true is that the technical team that was responsible for the 2012 and 2013 cars, apart from a few famous departures, is intact.
"We paid the price and we learned. Not the number of employees, but the efficiency of the work. I know teams with 850 employees who did not manage for years what others with 500 employees have done."
Lotus have not won a race since Raikkonen's victory at the start of the 2013 season in Australia.
