How the grid for the 2013 Formula 1 World Championship is shaping up

Williams were the last team to unveil their new car - the FW35. Pastor Maldonado (left), Valtteri Bottas and reserve driver Susie Wolff were present for the launch

The car was thrown straight into the thick of it, taking part in the second testing session at Barcelona's Circuit de Catalunya

Marussia launched the new MR02 during testing, driven here by new Brazilian ace Luiz Razia

New British driver Max Chilton has also been putting the MR02 through its paces in testing

French racer Charles Pic (left) and Giedo van der Garde of the Netherlands reveal the latest Caterham - the CT03

Caterham technical director Mark Smith said of the the CT03: "We have made a number of significant changes... This is the package we will take to race one in Australia. We will then bring new front and rear wings and a new diffuser soon after the start of the season"

Mercedes drivers Lewis Hamilton and Nico Rosberg unveil the Mercedes for 2013 that team principal Ross Brawn described as "a clear step forward in design"

BBC F1 technical analyst Gary Anderson said: "One area that is definitely working a bit harder are the front brake ducts, which are more elaborate"

Jean Eric-Vergne and Daniel Ricciardo will again be driving the new Toro Rosso STR8, which they hope can carry them and the team further up the field

Toro Rosso were marooned in the standings last year - well ahead of the bottom three teams but unable to challenge the midfield

Red Bull's RB9 car was launched at the team's Milton Keynes base on 3 February

The car has a very pronounced 'stepped' nose and more purple in the colour of the bodywork

Sauber's new C32 has a number of interesting design features and a new graphite grey livery

The new Ferrari-powered Sauber was revealed at the team's Hinwil base in Switzerland

Ferrari have launched their car for the 2013 season at their Maranello base - F138

Ferrari team boss Stefano Domenicali insisted they must be competitive from the start of the season

Force India launched the VJM06 at their Silverstone factory on the same day as Ferrari's F138

Driver Paul di Resta then took it for a spin around a damp Silverstone circuit

McLaren have launched the MP4-28 at their base in Woking

McLaren have followed Ferrari's 2012 lead in using pull-rod front suspension which creates a lower centre of gravity

Lotus were the first Formula 1 team to unveil their new 2013 car - the E21

"There is a hint of Red Bull about the rear bodywork treatment around the exhaust," said BBC F1 technical analyst Gary Anderson