[Griffo]

I have a 3.0 '6 also; in my experience for 15 x 7 wheels, 205-55's will be closest to stock (slight reducing of side wall height so ride is substantially the same feel with about the same "crispness" for turning, minimal effect on ride height and speedo, down-side is not too much available in this size, Dunlop did make this size in a decent street performance "flavor", in fact my street tires are this size but don't know if they still do).

for higher performance dry/street or track days, try 205-50 - lots of choices or with some trimming of the inner lip of the front air dam and paying close attention to the sharp metal in the inner rear wheel well arch, 225-50 will maybe fit (operative word - maybe) I've run both in R compund DOT legal "race" for track days, time trials etc. and think that 225-50 is a bit too much tire and next set I'll probably go back to 205-50.

the thing about R compound tires it that in dry conditions with some heat in them, thge grip is nothing short of spectacular, but in the rain they can be frightening (which is why I'm not a big fan of these tires as your everyday/street choice.)

also remember that the numbers (205-50, 225-50 etc.) are the manufacture's using the closets obvious size rating and that not every manufacturer's 205-50 is the same rolling distrance/circumference or width or even height is the same as any other manufacturer's offerings of the "same" size.

anyway, enjoy but remember now that you've started this thread and goten others "started", you really should post/let us know what size and brand you end up with...