Mercedes and Ferrari are the latest teams to have passed the mandatory FIA crash tests ahead of the 2013 season.
According to reports in German publication Auto Motor und Sport, Mercedes' W04 will have a smaller gearbox, a Coanda exhaust with different sidepods as well as a rear suspension designed to be sensitive to geometry changes to suit the new Pirelli tires.
Spain's El Mundo Deportivo reported that Ferrari's 2013 car has also passed the FIA's monocoque crash tests.
Earlier, Sauber became the first team to announce that its new car has passed the tests and that it was ready to begin winter testing in February.
