The stock wheels for the Fit are 16" diameter and this package is a 14" diameter.
Make sure the 14s will clear your brakes. I don't *think* it's likely to be an issue on the Fit, but on a lot of cars, you can't go down a wheel size due to brake caliper clearance issues. Make sure you've got at least an inch of clearance between your brake calipers and the wheel on the current wheels (should be easy enough to do with a flashlight, though you may need to jack/jackstand the car to get your head in to look). It's easier if you crank the wheels all the way to one side first to see.
- If I order online, they just ship to my house all ready to go and I can install them myself, correct?
Yup! Assuming you have a tire iron and jack. They just show up at your door with labels on them, usually in packs of two. I've done this, and it was wonderfully convenient.
- If I install myself, do I need any tools besides a torque wrench? (I'd need to buy that)
A proper jack is almost a requirement for this. You'll hate yourself if you try it with the dinky little jack that comes in the car. And I can't say I've ever used a torque wrench on wheels - they matter a little bit for aluminum, but for steel, just crank it down with a 4 way, check it in a few miles, and you're fine. IMO. Obviously don't be stupid and have a 5 year old tighten them or something.
- Is it worth getting the TPMS installed? If Tire Rack installs them, do I need to do anything about that when I put the wheels on my car?
You'll need to sync them up to your car. No clue how to do that. I wouldn't bother, but I only own one vehicle with TPMS anyway, so... most of my car life has been without such things, including on cars with pretty good leaks.
- Is this worth the hassle, or should I just go get winter tires at a local tire shop and skip Tire Rack?
I think it's convenient. You can get the tires, and install them on your schedule (which, for me, seems like it was always 8PM or so the day before leaving on a long winter trip). Call some shops to see what their prices are, but most of them will, by default, want to swap winter rubber onto your current wheels, which is silly. You can't swap it back yourself, and it's a lot of additional tire changes on your wheels.
Many thanks! I have put tires on a car before, but have never bought online, so this is all new.
It's pretty simple. Just be sure the 14s will fit.