Mercedes, who will also use the Spanish track to launch their 2015 car today, cruised to the constructors' championship last season, whilst Lewis Hamilton edged out teammate Nico Rosberg for the drivers' title.
A series of technical changes at the start of 2014 gave Mercedes a huge jump on their title rivals. However, with comparatively few tweaks to the rules this off season, there should be far more competition at the front of the grid.
Red Bull were the best of the rest in 2014 despite finishing nearly 300 points adrift in the constructors' standings.
Force India are the only team to decide against testing in Jerez, instead opting to concentrate on the second series of testing in Barcelona beginning on February 19.
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