Just got my Fit and looking to add wheel spaces. I like the way it looks with the wheels not so far in.

But when getting wheel spacers, do you normally just add them to the back wheels or do you add them to all 4? The pictures that I've seen of most of them look like they've only been added to the back.

 

Reducing offset is the means of pushing wheels out from the hub.. Changing wheels or installing spacers will do the trick.
wheel spacers that have lugs reduce the offset by their thickness. the tinest I have seen is 15mm, reducing the wheel offset from 52 or 53mm to 37 or 38 mm, much too little for front wheels and more often than not rear too. any spacers greater than 15 mm are treading in dangerous territory as fit wheels/hubs aren't designed for that much added stress on the hubs and bearings.
wheel spacers are also available without lugs and come in 3 to 10 mm thicknesses and merely fit behind the wheel against the hub.
Any of those are acceptable if your lugs are long enough. If you can't thread your wheel nuts on at least 8 turns torqued to the wheel your lug is too short. Most Fit will handle 6 mm spacers, availble at many auto parts stores.
good luck.
and it is best if you do the same to all 4 wheels.

 

i have a 12 mm hubcentric spacer with built in lugs. unfortunately, the oem bolts still stick out too much and i had to add +5 mm slip on adapters...

 

I have a concern with 12 mm thick spacers with lugs; it is too thin to carry the loads from the hub to the wheel. 15 mm is minimum, where did you get 12 mm ?
by the time you notch clearance for the lug bolt heads you barely have 1/4" of thickness to retain the lugbolts.

adding a 5 mm spacers, sure they aren't 6mm (1/4") means reducing your offset from 52 or 53 mm to 34 or 35 mm which should interfere with the fender on PEM diameter tires.

 

i got it from JDM land. i'm running +42 offset and the +17 adapter for my rear. no rub so far on stock dunlops.

 

I have a concern with 12 mm thick spacers with lugs; it is too thin to carry the loads from the hub to the wheel. 15 mm is minimum, where did you get 12 mm ?
by the time you notch clearance for the lug bolt heads you barely have 1/4" of thickness to retain the lugbolts.

adding a 5 mm spacers, sure they aren't 6mm (1/4") means reducing your offset from 52 or 53 mm to 34 or 35 mm which should interfere with the fender on OEM diameter tires.

 

When I had + 53 OE wheels I used 25mm hub centric adapters, rear only. After changing to +42 I switched to 10mm hub centric spacers and switched to 10mm longer studs. Lugs are pretty easy to change on the rear. No disassembly required, although 10mm longer studs were a little tricky to finagle into place. I'm not sure if 15mm longer will fit. I'd rather go this route before adapters in 15mm w/ a second set of lugs.

25mm with stock wheels looks nice. 20mm will work with OE alloy GK wheels if you want a little less. The OE lugs are a little longer overall than the alloy spacer but the OE wheels are recessed on the back and will work.

25mm have no issue with lug clearance.

 

I agree w/ Mahout, 15mm or less extend the lugs; 20mm minimum for adapters. Thinner than this and the adapter nuts are just too thin for confidence. A12mm adapter only leaves 8-10mm thickness of the 4 adapter nuts holding it to the hub. No thanks.