Can the logitech G25 be used with gran turismo 5 on the PS3?

May be...

haha im looking into buying gran turismo 5 and a PS3 but only if gran turismo 5 works with the logitech G25 but does it work? and if so how do i get it to work?

Mate, the logitech G25 was specificly made for Gran Turismo 5. Of course it will work!