I'm not positive on longevity of the studs, but they do have a few things going for them that other studded tires do not - they have "cushioned" areas underneath the stud that are designed to reduce noise and I'm assuming they have a positive impact on stud life. Regarding the slippage - it was slightly noticeable, but only when I first switched the tires. I've adjusted my driving habits slightly to account for this - mostly in corners, not so much accelerating (but then again I typically don't try accelerating too quickly). I imagine in a car other than a hybrid where the drivers have heavy right foots, it would be more noticeable while accelerating. In the patent application for the anti-skidding studs, Nokian mentioned a trade-off in acceleration grip for stopping grip (US Patent Application# 20150197122, section 0009 in "SUMMARY OF THE INVENTION", page 4 of the PDF on the USPTO website) Regarding the patent though - from what I can see, the patent is mostly about the studs in the center of the tire, not so much on the shoulder. And this is still in the application phase right? It doen't look like its been granted yet. I also couldn't find any other patents from Nokian that are similar to this or even any other patents that are for the double studs that could have been licensed to them. I've only checked the USPTO though, nothing internationally. They rant and rave about their "Patented Double Stud Grip" on their website (see website snip below), but from what I can see, the patent is more about the center studs and not the double studs. If there is someone with more patent expertise, please chime in because I really would like to know. I came across this grain of salt before purchasing my tires, and I still wanted to buy them and am happy I did.
I'm not even sure if they were take-offs, they looked very new. Still I would suspect they are, but I saw no evidence of old weight marks for example. $70 seems a good deal, I think they made it up with the complete package, profit on the snow tire sale.
Just a heads up on using dB for sound - every 3 dB increase is double the noise. The video shows that the Nokian studded tires are about 6 dB louder than the non-studded tires. That's 4 times louder. That is quite a bit more noise.
Based on all the feedback, I decided to get a spare set of wheels for my Michelin X-Ice 3 snow tires. Bought used American Racing tires that had been used on a 2010 Corolla. Learnt a lot of lessons about after market tires, spacers, rings, and lug nuts!!! Finally have the snow tires installed. My advice - stay with OEM wheels if you can. Aftermarket wheels requires tooo many factors to consider and resolve!
I've got PIP rims waiting in the wings. If/when I replace the snow tires, I might swap them for the corolla steelies, looks a little classier. Still, there is something about black steel rims that says, you've go SNOW tires, lol.
I get five years out of a set of Studded Nokians on a prius, they don't wear fast or unusually. When I accelerate I let the situation decide the amount of wheel slip, if I need to get out of the way of an unseen speeding car, the prius using 100% of the available electtical energy and the ICE is rather fast, an extra slight slip for the studs is much less traumatic than going over a bumps as the brakes are applied..what brakes? When at speed, the studs have no effect on acceleration, the noise is relevant to the ability to stop on ice, and start on ice. Summers at speed I listen to NPR with the volume set at 9, winters 11. Prii are rather quiet, safety first
I would like to close this thread. I went with the advice on this forum and got myself a set of spare wheels for the winter tires. Did not use TPMS, so am living with the TPMS light coming on. Hopefully I can go back to OEM tires in a couple of months and put the winters in storage.
To Charged Up and others: This year I am also going with Hakkapeliitta 9 studded tires. I was not happy with the performance of the Hakka R2s on ice, and, quite frankly, did not feel much safer on all of the ice (A LOT of it here last April!) than I would have with all seasons. Concerning the sound video, I decided to do more comprehensive sound testing, to compare the Toyo NanoEnergy A29 stock tires that come with my Prime with the Nokian Hakkapeliitta 9 studded winter tires. The 4K video is 2.8 GB and almost 13 minutes long because of all of the comparisons and road tests: Sound level recorded inside 2017 Toyota Prius Prime while driving on normal tarmac (October 16-27, 2018) (need to download manually and play in whatever program that you have that can play .mov files)
Ypu want to drive a dream go ahead spend the money and get a set of Michelin .Your driving experience exceeds that of flying an airplane or space shuttle in full orbit] Plus those tires will last almost a life time of you treat them with 303 water based uv protectant. Put it inside the tire a heavy coat and dunk them . About every 30000k slosh so.w more on My tires have 110k and still have deep treads and ride as smooth as polished glass. You see those tires are made carefully and balanced like a babys behind. I have tried all the other good tires but now everything is Michelin. It takes an old 1st gen and makes it feel brand new.