Ugh Winter tire size question....Sorry....

Regardless of whether your car came with the 15" or 17" tires, it'll do fine with 15" snow tires. 195/65R15 is the stock 15" size, and I'd stick with that. You really don't want to go wider in snow tires, narrower tires will grip better in snow.

I went with Michelin X-Ice, very satisfied with them. Here on the west coast it's rare that we get snow, and the X-Ice are very smooth/quiet on bare pavement, and decent for fuel economy.

FWIW, I got them mounted on Corolla steel rims, without tpms, and with extra, utilitarian, galvanized open-ended lug nuts, both supplied by a dealership. You might also consider aftermarket alloy rims, but if your interest in steelies, here's some info:

Corolla steel rim, part no: 42611-02471 (2003-2008 corolla or matrix, CE, LS, S)
steel rim lug nuts, part no: 90942-01007 (plain, open-ended, galvanized)

The rims were $70 apiece (new) and the set of lug nuts about $30. You can use the regular nuts, but they will look a little odd, stick out too much.

One issue: the centre hubs are open, exposing the wheel nut. I ended up capping them with a 2" abs end cap, black plastic you can get at Rona, Home Depot. It's a slightly loose fit, but with a makeshift gasket (section cut from old bicycle inner tube) pushed over the centre hub of the rim, the caps are a snug fit and stayed on.

 

Last year, around this time, I bought a set of Blizzak WS80s, popped them on a set of 15" steel rims from TireRack.com ($52/rim (included lug-nuts (it's most important to use correct nuts)) for my 2009 Gen II (Touring), and it was almost as good as having AWD - the Blizzaks are amazing - I did a fair amount of research (see threads passim). I've also seen good reviews of the X-Ice Xi3s, but I thought the WS80s had the edge. Last year, I took advantage of my local Toyota Dealer's "Buy 3, Get 1 for $1" offer (which I just saw a flyer in the mail for this year's offer)
The original 16"OEM rims were shod with Michelin Energy Savers, but, being almost worn out, those tyres were just about useless in the previous winter's unusually high amount of snow we had here in the North East (USA), the OEM rims were fitted with TPMS, but for last winter I just ignored the flashing TPMS light when the steelies were on.
By having a second set of rims for winter, the tyre-beads are not subjected to the same wear and stretching which occurs when being taken off and on twice per year, and I didn't consider it economical to swap or change the TPMS sensors twice/year. Also, having really good snow tyres for the winter, meant that I could get a set of good summer tyres which didn't need to be "all-season" (I found that some experts advised that "All Season? …there just ain't no such thing…" and OK, "All Season" provides the convenience of not having to change tyres, but it's always a compromise! I hope this helps, and you might find "search" to be useful since much of this has been covered elsewhere! - Wil

Edit: I should have read your post right to the end, but I thought I'd mention that when I replaced the worn out Michelin Energy Savers at the end of last Spring, I got a really good deal (Town Fair Tires) on a set of 205/50xR16V Antares Ingens (no, I'd never heard of them either!). The 4 tyres, plus fitting, plus road hazard insurance, 50k mile warranty plus free changing for the time I own the car, cost about half the cost of a set of Michelin Energy Savers (which weren't available or discontinued in my size). The Michelins are great tyres, but their weakness is that the tread outlasts the tyre-walls, and mine were starting to develop very fine cracks on the side-wall (also see my previous note re. compromise) - also the Antares are much smoother and quieter then the original Michelins.
Also, I didn't need adapters (my Prius is a 2009 Gen II)

 

The "experts" are correct for the most part. HOWEVER, there ARE "all weather" tyres. Nokian WRG3 and now the Hakapalita has been re-engineered (won't wear excessively on warm dry roads). They are both "winter tyres you can use in the summer too". I love them, and bonus, they are hard to "aquaplane". So they are very nice in rain.

As above, use the 15" size as it's less expensive and available in more makes. The overall diameter is almost the same in the two Prius sizes (Prius come with either 17" or 15" wheels - the 17" is a lower profile tyre to keep the overall diameter close. It has handling advantages (you would never need that in winter - you can't corner fast on slippery roads), but would in general ride rougher with more road noise as the sidewall is stiffer. The taller sidewall in the 15" size helps to keep the rim out of the muck, most of the time.

Oh, and it's been snowing here for two days now. The roads have finally cooled off enough the snow isn't melting on them, so it's starting to build up. Don't you just love early winters? Some of our trees still have green leaves on them!

 

There was someone here got 17" (generic, extra lug nut holes, oversized centre hub opening) steel rims, 215/45R17 snow tires (X-Ice IIRC) and TPMS sensors. He'd sold the car or something, anyway he was trying to sell this combo. Ugh...

 

When you first start the car you will see a small square cross section of a tyre in yellow on the dash. That is the TPMS warning.
And yes, all Prius have it. The sensors are part of the metal valves in the wheels. There is no pressure readout nor is there an identification of which wheel is low. There is no sensor on the spare.

 

One thing: in the 'States keeping the TPMS functional is mandated. In Canada it isn't, so far.

 

I've had no problems getting my inspections done, but they're always due at the end of June when the summer wheels (inc. TPMS) are being worn!

 

Yeah as long as you can find a sympathetic tire place. I think they can get nailed?

 

I bought the summer shoes from the local TownFairTires, so they know about my TPMS-less winter steelies, and I warned them about ignoring the nag-light during the snow-season, and they said "No problems! That's what most folk do!" (…well, I guess I'm cheap! …there! I've said it!)

 

Go with 15"s, Hight will still be the save if you change the diameter, as the sidewalls will be lower. In the winter the above posts are right, don't go above 195, thinner is better to cut in the snow. Also, in the winter it is not a fashion show, getting 15's you will have a lower cost.

P.S. I live in New Brunswick, lots of snow here in the winter months.

Thanks

 

Forgot to mention: the 215/45R17 optional size is actually a slightly smaller outside diameter. And the tires are at least 50% more expensive. And the aforementioned poorer snow traction.

Just an all 'round bad idea, lol.

 

For what it's worth, last year I bought four slightly used snow tires mounted on 15 inch steel rims that were on a 2011 Toyota corolla. No TPMS. Paid $300. I bought cheap wheel covers from eBay to cover the hubs. They worked great getting up my steep long driveway with two inches of snow on the ground.

 

I keep toying with the idea, just never get around to it. Think I actually like the bare/black/steel rim look with the snows, lol. I've looked them up on Amazon though.

 

I got the Corolla steelies option from you. Thanks Mendel.

 

Just to give you another opinion, we have winters very snowy here in Finland. I've been running 17" wheels like "always" with no issues. Tires are 215/45/17. I'm pretty sure you won't notice any difference in traction - even if it should theoretically be better in 195 wide tire. Of course the price is different so I'll leave it up to you to decide. Drive safe, whatever you choose!

 

Is that metallic white (Blizzard Pearl) or non-metallic white (Super White?). Looks sharp in winter.

What 17" tires then? I'm guessing one set for year 'round, some sort of Nokian "all weather"?