Lotus's Gerard Lopez does not entirely blame Renault for lackluster 2014 season, but sets his sights higher with Mercedes engines.
Lotus owner Gerard Lopez is targeting a much brighter Formula One future with Mercedes power in 2015, and admits mistakes were made last year when it struggled with Renault engines.
The Enstone team, fourth overall in 2012 and 2013, slumped to eighth in the constructors' standings last year.
Ahead of this week's crucial test sessions in Barcelona, he told France's Auto Hebdo: "Our new Mercedes engine will make the difference, although Renault was not solely to blame for the disastrous 2014 season."
He revealed that, having shed 100 staff a year ago, Lotus has now rebuilt with 50 new signings, "mainly in aerodynamics and CFD".
"There was so much written about good people leaving," said Lopez, "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,
"We paid the price and we learned," he added, referring again to the poor 2014 season.
"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."
But Lopez was also critical of Renault, who after the Lotus split and the Caterham collapse are now supplying only the Red Bull-owned teams.
"It would have been useful for them not to focus their efforts on just one team," he said.
Early promise from new challenger
Lotus is now hoping to rebuild in 2015, and the driver feedback about the tidy new Mercedes-powered E23 has been positive so far. "It's a less aggressive approach," Lopez revealed.
"This is not only because we went too far with the E22, but we also scored an own goal with developments favouring better top speed."