HONDA FIT 2008 ...upgrading to Alloy 15 inch, 100 x 4 bolt, 55 offset wheels
 

I suggest reading up on WIKIPEDIA about Tire codes ...

The ones for the SPORTS are rated to H - 210 km/hr , meaning 210 km
is the max speed.

The ones on the DX and LX, are 14 inch steel, with 175 65R 15 inch
tires whereas the Sports which is $5k more expensive as a dealer
model, with ac, power locks and mirrors, etc. has P195 55 r15 tires
....rated 84H.

The pattern on both is 4 x 100 bolts, but .. the difficult part is the
55 cm offset.

I suggest reading this here:


http://www.1010tires.com/WheelOffsetCalculator.asp

Also, some hints are http://www.carmodifier.com or

http://www.tirerack.com/ for purchasing.

I think some good examples are perhaps the Kumho tires
and the Enkei wheels or the FAST brands, for example.

There are many others ... if you proceed outside of the dealer, the
bolts are included and the mounting, so you remove 60% of the price
margin overhead that otherwise the dealer would charge you for the
same thing.