Mercedes will switch Michael Schumacher's car for next week's Spanish Grand Prix to try to get the seven- times Formula One champion back up to speed.
Team principal Ross Brawn says the one Schumacher had got damaged during the first few races and they repaired it as best they could at the races, but now they're back at base they're going to re-introduce the test chassis and he'll be using that in Barcelona.
Brawn says the wheelbase will also be changed to improve weight distribution, and Mercedes are also planning a major aerodynamic revamp for the first race of the European season after four in the Middle and Far East.
Schumacher, a winner at Benetton and Ferrari with Brawn as technical director, is making his Formula One comeback at the age of 41 after retiring at the end of 2006 with a record 91 race wins.
The German has been outqualified and beaten in all four races to date by team-mate and compatriot Nico Rosberg, with concern mounting that Schumacher is finding it hard to replicate his form of old.
Schumacher finished 10th in the latest race in China while Rosberg was third after leading early on.
