Sauber is preparing a new lightweight chassis for the Spanish Grand Prix, AUTOSPORT has learned.
The Swiss team has been unable to hit Formula 1's minimum 691kg weight limit so far this year, which has been a significant factor in it struggling to get on the pace with its C33.
But as part of a major development push, it is working on a host of weight reduction measures that should be ready for the Barcelona race in May.
These changes are estimated to shave around 20kg from the car, with 10kg of weight worth around three tenths of a second over a lap.
Sauber team principal Monisha Kaltenborn told AUTOSPORT that the team's focus now was on the issue of weight.
"We are planning a big upgrade for Barcelona, but on both coming races [in Bahrain and China] we will be especially introducing measures on the weight side," she said.
Sauber is one of four teams that is yet to score a point so far this season.