To be honest you are asking a lot from a tire. They do have some compromises that have to be made to focus on a specific purpose, ie. dry performance driving vs driving in the snow/winter. If everything is a concern, which it seems, then I would prioritize safety. People are questioning the validity of W rated tires, but you have only known your Prius from that perspective. The 17 OE wheels do come originally with W rated Toyo Proxes A20, a high performance tire to say the least. Just because it is rated to such high speeds, does not mean you are not benefiting when you are driving those switchbacks you refer to at 35 MPH. Race car drivers are not always running at top speed, and they are benefiting from the performance tire at all speeds. You are concerned about those times when ice/snow might be on the road, and longevity of the tire conflicts with this. If you buy a faster wearing tire you most likely spend more, but you can't safely drive around on low tread tires in bad weather conditions. Longevity conflicts with safety in bad weather when the tread starts to wear down. You seem happy with the current tires. If I were you I'd look at the performance group that they are in, on TireRack that would be Ultra High Performance All-Season. (To me personally, I would go RunFlat, but that's just me, and I'm weird like that. I'm always concerned about when I'd have a situation where I need to change/repair a tire, even though I seem to have a higher percentage of issues with RunFlats, read 2004 Sienna AWD with no factory spare.) BTW- Costco is one place that will not put lower speed rated tires than came from the manufacturer. They consider this a liability.
Toyota uses a variety of 17" tires. Ours came with Michelin Pilot HX MXM4. They're way down the survey list on TireRack, but seem fine on all fronts, at least to me. One thing, if you're dealing with icy roads in winter, consider separate snow tires. There's a Corolla steel rim that works.
This is news to me. I may be mistaken about later years but the Toyos were definitely OE in 2012. MT2L03 ?
They use more than one tire I think, depending on region, availability, cost and so on. BTW I had a typo: I should have typed Pilot HX MXM4.
Just a comment on researching tires. TireRack reviews are entirely written by their customers after purchase and are subjective at the best and simply ridiculous biased statements intended to justify their own recent purchase. What are they comparing the new tire to? An old worn out tire they just removed??? Bogus. Nobody goes to a tire shop and tries out a half dozen tires on their car in varying conditions. Ratings are therefore simply made up. There are very few articles that use controlled research in testing tires. A few of the auto mags do it but only rarely. Of note, the results of those controlled trials rarely coincide with the fanboy reviews on TireRack. If someone hired a SCCA veteran to test tires in varying conditions in a user blinded manner I would be very interested in their advice. To have a bunch of lemming wannabe reviewers yammering on about how great their new tires are (generally compared to the ones the factory engineers selected) is simply a pile of baloney. No help at all.
There are quite a few even, candid reviews. Besides the self-congratulating reviews there's also some complete pessimist trolls. If there's a fair number of reviews you get the prevailing opinion.
I'm pretty sure TireRack has a fleet of BMW 3 Series which they use for testing. I've even seen pictures of their testing grounds. MT2L03 ?
And performance on a FWD car like the Prius may be a bit different than on a BMW 3 series RWD. And slightly different sizes, even in the same model tire, may also be different. So even the TireRack comparison tests may not totally apply. But better than nothing. I was at my dealers today buying $42 worth of wiper blades for my wife's Avalon and asked when the best time to buy tires was if I were getting 4 Michelins. The service manager said all through October they have a 4 for the price of 3 sale.
Comparative traction is comparative. To compare using a Prius and a 3 Series would be meaningless. To compare on two 3 Series and then ask how that applies to the Prius: Well, if you floor it and there is more grip on the 3 Series, most likely there will be more grip on the Prius. If you slam on the brakes, this is more obvious as both use all 4 tires to stop. Tire size and tread pattern difference due to this may make some difference, but there are other factors such as tread compound and design of the shoulder area that would be similar. Overall I would take the information given as significant, but to each his/her own. A simple example. Which tire would you pick if performance driving was important to you, a V rated tire or an T rated tire? I don't even need to know the brand to tell you which is more likely to perform better on a switch back road....
The magazine comparisons can be for about 9 qualities. Lets see if I can remember some of them for an A/S like the OP is considering: Handling dry Handling wet Stoping dry Stoping wet Noise Rolling resistance Longevity Snow traction Ice traction Handling being one, the interaction between a tires characteristics and the suspension design can make a difference. I know of several car brands where tire manufacturers make a tire with special characteristics to qualify for use with that car maker's expectations for the car. For example, Michelin makes a tire with the same name and model number for general use but with a special design of that same name and a different SKU for one designed for a Porsche (the N- qualification). Would the tire pressure for a BMW tire test be the same for a Prius where people typically add pressure to get better MPG? And would the results be different with different pressures? Buyers reviews are always suspect because they are possibly comparing old to new tires with fresh balancing and pressure, even maybe a fresh alignment. I totaled a car because I hit a patch of early morning ice from dew on Thanksgiving weekend in the DC area. The only patch on the roads, No warning. All of a sudden the car wouldn't stop from maybe 35MPH. I had on the wrong kind of tires for those conditions even though they were perfect for the day before or even an hour later (Ultra High Performance Summer). I've driven the western switchbacks with no guard rails. Given what the OP's conditions are like, I'd say your money or your life and have two sets of wheels/tires and put the winters on when there was even a chance for snow/ice conditions.
We have a set of 215/55ZR17 98W rating tires on our Prius. They are a little taller but the speedo is right-on compared to the Garmin GPS. They were take-offs at a BMW dealership ( I believe from a Z4 but not 100% sure) 95% tread. they run nice smooth. And the price was right.
Would the weight of a Prius be the same as the weight of a BMW? No. We can go on forever like this. Would the tread compound be the same, yes. Are we talking about vehicle specific tires that TireRack is testing, no. MT2L03 ?
Your speedometer may be "fixed", but your odometer is now off, by around 3.3%. Also, your tire outside radius has increased by over 3/8". The speedometer "error" is legislated: the object being to get people to slow down a bit. Not the end of the world, you've effectively made the "gearing" taller, fwiw.
'High Performance' refers to dry traction usually and the usual trade-offs are fuel economy and longevity. Icy mountain road driving should (in my opinion, of course) be handled by either a dedicated set of winter tyres or an all season that is the best of the bunch in winter metrics. I'm in a similar situation as you and am hoping that the Michelin 'CrossClimate' will make it to US shores before winter.
I will have to zero the GPS and zero the Prius and do a long run to see, I thought if the speedometer is corrected the odometer will be corrected.
Unfortunately I think no. Odometers HAVE to be reasonably accurate, with the stock tires. Honda got into hot water over that with some cars: odo numbers were running owners out of warranty prematurely. Speedometers have to be accurate, or read a bit high. The big no-no is that they read low. So manufacturers err slightly high, in the middle of the range. Really all it's doing is giving feedback to the driver. With larger tires your car thinks it covering less distance than it actually is.
