before the end of the season. GP8 An update of the GP7 design, Ducati's entry for the 2008 MotoGP World Championship was tested first in February 2007. For purposes of avoiding chatter which was encountered on some occasions with GP7, the rigidity of the GP8's frame was altered, although further details of relevant modifications are not disclosed. In addition, in an attempt to reduce an effect described as "pumping", some modifications to the bike's suspension geometry were made. As with its predecessor the GP8 contains a four-cylinder 800 cc engine with desmodromic actuation of its 16 valves. The engine has improved mid-range response and top-end power compared to that of the GP7. Throughout 2007, Ducati tested a special fuel-saving clutch arrangement which disengaged the clutch during braking and reduced fuel consumption, however the arrangement was not incorporated in the GP8 as various advanced lubricants and fuels used with the GP8 are believed to provide comparable fuel savings, while decreasing internal engine friction and increasing maximum power. In race trim, the bike recorded an official top speed of at the 2008 Chinese motorcycle Grand Prix. GP9 The GP9 was Ducati's entry for the 2009 MotoGP World Championship. Ducati began testing it on track prior to May 2008. On 9 June 2008, Ducati publicly rolled out the Desmosedici GP9 for testing at Circuit de Catalunya. A distinctive feature of GP9 is its carbon fibre chassis, representing a departure from Ducati's traditional steel trellis chassis. Although carbon fibre chassis were tried in mid 1980s, currently no other MotoGP racing team uses them. GP10 On January 15, 2010, Ducati introduced the GP10 for the 2010 MotoGP season. Development concentrated on improving engine longevity, to keep within new engine restrictions, and rideability. Most notably, the GP10 makes use of a big-bang firing order for the first time since the Desmosedici changed from the 990 cc to the 800 cc engine capacity. Ducati also redesigned the fairing, first seen at the 2009 Estoril round. GP11 On January 12, 2011, Ducati introduced the GP11 for the 2011 MotoGP season. The bike was raced by Valentino Rossi and Nicky Hayden. GP12 On March 19, 2012, Ducati unveiled the GP12 for the 2012 Grand Prix motorcycle racing season which incorporated new displacement standards of up to 1,000 cc in capacity. The bike was raced by Valentino Rossi and Nicky Hayden. GP16 The Desmosedici GP16 was unveiled in February 2016.