The closest tire size to OEM for your Fit odometer / spedometer / fuel economy that is readily availible is:
185/60r/15
Most people don't realize that the "r" size is a ratio. A 205/65r/15, for example, will have a different Diameter and Circumference along with the different Width so it affects your Odometer and Speedometer.
Most people just think the width measurement has no other bearing on the other specs but it is untrue don't listen to them.
If you have a warranty to respect, changing the tire from stock specs may cause you issues. It would be considered rendering the Odometer inaccurate, and they can claim greater wear on driveline components, transmission, and engine strain.
While this is all truly negligible, they can make warranty claims tricky.
Never show up on a warranty claim with odd sized tires, a snakey dealership will immediately write this on the docket notes, and take photos, then probably get you to sign the work order. And POOF there goes your warranties.
But I wouldn't know first hand, just something to keep in mind. Contrary to popular belief that a Dealer takes any work they can get, they DO prefer when the client pays the bill, not Honda corporate.
Forgot to add: I use 185/65R/15 for my Winter tires to give slightly more clearance for deep snow and the ride is SMOOTH but note that wheel well slush and ice are that much closer to the tire so you have to kick the wet slush off the fender wells before a deep freeze to avoid breaking push pins on your plastic fender liners (never happened to me though just a thought).
Steer clear of OEM friendly Pirelli Snow Controls, they are horrible on ice. I have to snap the car into neutral and push the car a few feet backwards during a freeze as it will spin on the ice indents in my parking spot, and I have to peel my tires up icy slopes. I use Yokohama IG20 185/65R/15s now and NO ISSUES RIDE GREAT.