Why does Kazunori Yamauchi, creator of Gran Turismo, get special dispensation from Sony when he makes a game? Because each main Gran Turismo release has sold roughly 10 million copies - or more.

The best of the bunch is Gran Turismo 3 A-Spec, released 2001, with a gargantuan 14.80 million copies sold worldwide.

Gran Turismo 4 and the original Gran Turismo are almost neck-and-neck behind GT3, with 10.86 million and 10.81 million sales each, respectively.

Yamauchi's second game, Gran Turismo 2, didn't quite make it past 10 million sales, but finished close with 9.34 million sales.

Gran Turismo 5, the most recent instalment, has now shipped 5.5 million units.

Those are the core releases. Preceding the fifth game was Gran Turismo 5 Prologue in 2008, which shifted a significant 4.81 million copies. In contrast, Gran Turismo 4 Prologue sold 1.34 million copies.

There's an interesting geographical twist to the figures, too. Whereas record holder Gran Turismo 3 sold the most copies in America (7.14 million), every other Gran Turismo has done bigger business in Europe - barring GT2, which narrowly sold more in the US.

Typically, Yamauchi has opted for lower numbers of cars when launching on new PlayStation hardware: PSone debutant Gran Turismo 1 had 178 cars (according to Wikipedia), a figure Gran Turismo 2 took to 650; PS2 debutant Gran Turismo 3 had 180 cars, a figure Gran Turismo 4 bumped to 722.

Gran Turismo 5, however, bucks that trend like a steroid-pumped donkey, with a whopping roster of 1031 cars. I dread to think what Yamauchi will insist goes in to Gran Turismo 6.

Gran Turismo lifetime sales are below:

Gran Turismo (PSone 1998) - Europe: 4.27m, US: 3.98m, Japan: 2.55m, Asia: 0.01m
Gran Turismo 2 (PSone 2000) - US: 3.96, Europe: 3.65, Japan: 1.171, Asia: 0.02m
Gran Turismo 3 A-Spec (PS2 2001) - US: 7.14m, Europe: 5.76m, Japan: 1.89m, Asia: 0.01m
Gran Turismo Concept 2001 Tokyo (PS2 2002) - Europe: 0.94m, Japan: 0.43m, Asia: 0.13m, US: N/A
Gran Turismo 4 Prologue (PS2 2004) - Japan: 0.79m, Europe: 0.39, Asia: 0.16m, US: N/A
Gran Turismo 4 (PS2 2005) - Europe: 6.40m, US: 3.02m, Japan: 1.27m, Asia: 0.17m
Gran Turismo 5 Prologue (PS3 2008) - Europe: 3.04m, US: 1.13m, Japan: 0.53m, Asia: 0.11m
Gran Tursimo (PSP 2009) - Europe: 1.19m, US: 0.67m, Japan: 0.32m, Asia: 0.04m
Gran Turismo 5 (PS3 2010) - Europe: 3.56m, US: 1.25m, Japan: 0.55m, Asia: 0.16m