16.5 million lol?

Its possible.

A shooter can do 7.7 million in NA, a racer could do more in Europe.  Genre is open to more people and EU alone has 200 million more people. 

With every release European GT sales have grown. 

NA?
I'd say 3.6m

im a big nascar fan and dont see gt5 as a purchase for that reason gt5 wont have all the nascar tracks may not have half of them and wont have 43 car fields i think it has like 10-15 of the actual nascar drivers

ea is done with nascar rumors are that papy or some one else will return with a epic nascar game in 2011 so nascar fans are looking forward to that although nascar fans should be into sim racers anyway so it maybe a + for them

and no nascar is not for southerns only

i dont see 6-7mill look at gt4 and look at 360s top sim racer it only has done 2.5 and FM3 for 360 a pretty good sim racer only managed 1 mill in americas so far

i c 3-4 maybe 5m unless theres serious bundles sim racers are not as big as they once were
FPS is where is at this gen

ha ha just saw most of the posts up there if ur right u will have a epic thread with every1 doubting u but u might have to wait a long time to bump it

64,434,453

Wii and Xbox owners will buy it just to show off.

The previous Gran Turismo iteration sold around 10.5 million lifetime. Gran Turismo 4 was released on February 22th, 2005, while the userbase of the PS2 was about nearly 85 million according to
http://vgchartz.com/hwcomps.php?cons1=PS2&reg1=All&cons2=GC&reg2=All&cons3=XB&reg3=All&start=38039&end=38417&weekly=1

If the tendency keeps up, and considering this is the best-selling franchise for Sony... just take a look at GT5 Prologue...

http://www.vgchartz.com/games/game.php?id=6972&region=All

You can see there's a keen interest in Europe. Considering the small userbase the PS3 have (likely 34 million when GT5 will launch) versus the 85 million PS2 when GT4 launched, I think, more likely, that it will sell more in Europe, and LTD about 7 million GT5.

3,5 millions Europe
800 000 Japan
2,7 million Americas

It is also possible for me to win the lottery one day. It's just that the chance is very slim and it may never happen.

By its self of course its not a reason to buy, but its a nice extra reason for buying it with all the other features.  Iam sure them nascar fans would not mind playing GT running a Cobra or a Vett whoopin on some imports and overpriced supercars.   

Comparing GT to other sims is pointless, since day one its been in a league of its own.  Sims racers were never that big people, its GT thats been big.  All other that have tried have faield to achive even half the sales GT regularly does.   Forza sold 1m and GT4 did 10, F3s sales mean shit all to GT5 sales. 

Ok you did some reserch so a good post.  But he GT4 user base argument is flawed as hell and has been destroyed. 

GT3 released on a tiny 12m user base, sold 14.7 million.  

- PS3s user base will in no way hurt GT5 sales. (MW2 did 9 million in what 10 weeks, came out on 34m 360 user base)

- You need to look in at the differance between the first GT of the Gen and the second.  First of a gen GT has historically sold better regardless that the second one had a massive 50 or 80m user base to sell on.

GT5p is nearing 5 million (with psn) dude, just saying.