Considering the userbase, the developing time, the competition & substitution...could GT5 be the lowest selling GT game of the franchise?

The user base argument is completely invalid and irrelevant. I don't understand what development time has to do with sales. Competition has always sold the way it has been doing recently in the past. Its not like there is an upswing of peopple jumping on board with those games.

That being said, yes, it COULD be the lowest selling game in the series. But not for the reasons you list.

I can see two possible reasons for this to happen

1) GT5 ends up being crappy. Unlikely.
2) the global population of racing sims fans has decreased since the last instament of the game. Possible, I guess

As far as MGS and GOW go, they were never huge franchises in the first place, there was always room for growth, I don't think the GOWIII/MGS4 selling more argument holds any water as far as GT5 is concerned, imo of course

Logically, of course it should be the lowest selling, I know we hear about userbase not mattering, and it most cases it doesnt, but if you had a PS2/PS1, you HAD to have a GT game, I don't think PS3 has the same fans in it's userbase anymore, there were a lot of casual PS2 people that bought GT.

I reckon it'll do 8 -10, Halo and MW2 have proved a game can do those sales on that kind of userbase, the only reason I don't think it'll do as well as previous games, is that I just don't think racing games are that big anymore.

1.1mil is too conservative, considering Prologue did almost 700k in its first week without including digital downloads.

GOW3 managed 1.1mil in its first week, and Kratos doesn't command anywhere near the same power as the GT franchise. Moreover, GT5 will release in the holidays vs GOW3 releasing in March.

@ Bayuum: it's worth considering several things...

• it's the first full Gran Turismo of this generation and that always a huge plus (CGI pointed out two good examples, and there plenty more, where a franchise's first release on a new generation defies expectations)
• install base isn't all that important - it's the first 20-30 million that contribute most of the purchases of hardcore or flagship franchises; think of it as a graph where the line suddenly curves steeply upwards - the install base might take off sharply from 40mil to 100mil, but this doesn't affect the sales of a title like Gran Turismo proportionately... not even close
• the simple fact that Prologue has sold ~4.5 million copies (inc. digital downloads) in 2 years... that's an expensive demo achieving an 8% attach rate... crazy...

yes, the game would need to play catchup for years to get to the other gt games

It just has to beat GT:PSP. Not that difficult in my humble opinion ;).

Yakuza 4 - first week = 380k

MGS4 - first week = 480k

Gran Turismo is undeniably larger than either. GT5 will probably open to at least 550k first week over there.

I just can't see how you can logically stand by a potential opening week of 1.1mil when Japan alone will contribute approximately half of that.

I agree,

Japan - 600k
America - 800k
Europe - 1.2 mill

Roughly ..

That's fair enough - I completely agree and accept that racing as a videogame genre has lost a great deal of popularity in America.

That said, how curious about America are you?

It's just, if we take ~600k for Japan and, for example's sake, ~1mil in Europe and then we say that not a single copy of GT5 leaves the shelves in America in the first week... we still hit ~1.6mil - that's higher than the top end of your prediction and we're not even including America...