I looked around on the Fit Shoes forum

 

Yep the tires should fit. The only spec you have to watch out for is the width of the wheel. Unless you fancy the "stretched tire" thing, there's an acceptable wheel width for most tires under normal conditions. Based off Toyo's website/PDF (I'm sure it'll also apply for most other tire makers), that acceptable range of wheel widths is within an inch, e.g. 6.5"-7.5".

If you stick to the stock wheel width, or deviate +/-0.5" from it, you should be fine.

HTHs

 

Tires should no problem, you are most likely running 195's? So 195/25.4 = 7.7" wide. Any wider than a 7.5" rim width you will be "stretching" the tire, but feel free to go as low as 6" for rim width. Ideally, like Type 100 was saying, you are looking for a rim between 6.5" and 7.5" wide.

Couple things to watch out for when selecting new rims, try to go with +42 offset or higher if possible. Although with 15's you could get away with less, better safe than sorry. If you do want to go larger than 15", I would highly recommend +45 or more.

https://www.fitfreak.net/forums/fit-...el-thread.html

The second is the bore, you want to ensure the rims will fit over your hub. Generally if you are buying new rims the seller will already be able to match them up and if the bore is too large they can fit in a set of hub centric rings (not to worry, they are just inexpensive plastic or polyurethane rings to fill the gap).

https://www.fitfreak.net/forums/fit-...ric-rings.html

 

Buy 15x7/45 wheels that fit your FIT, bolt circle, 4 bolt. hub bore, and dish that clears your calipers and suspension links. If you buy tires get 205/50x15's. Your 195/55x15 or 205/50x15 tires both will fit the 15x745 or the 15x6/55 wheels.

 

Oops, looks like I answered only half the OP's questions...heheheh

Yep, what Sugarphreak and mahout have said
With regard to the lug/bolt pattern, our Fits need wheels with 4 holes with a PCD (pitch circle diameter) of 100mm. Usually they abbreviate this as "4x100."