Downsized from 19" to 17" and somehow... ride quality is worse?

I bought the 215/55R17s specifically to match the original diameter - the difference is less than 0.4" (26.7" vs. 26.3", for 195/50R19 and 215/55R17). I would have gone for 225/55R17 for the speedometer's sake which would be a perfect match to the original, if I could have found it locally with a good rim set (and at the right price). The sidewall has also increased by more than 1" inch.

Also, I don't appreciate the insinuations and assumptions about motives. The CC2's have one of the lowest rolling resistance numbers out of all others in the all-weather category - which is the only category I'm considering for new tires given the increasingly unpredictable weather up here in Canada. It is also consistently in the 5-10% of all-season tires for rolling resistance. I'm actually not sure if Toyota bothered to supply LRR tires on the 19 rims (perhaps on the Ecopias (?) on the OEM 17" rims), but even so I would not be surprised if there's very little difference between the CC2's and the OEM Toyo Extensa's A/S II, if not the CC2'S being better.

And contrary to the insinuations, I chose the latest Prius specifically for fuel economy, increased pure EV range compared to previous gens, and partially the interior features (I'm the kind of guy who really doesn't care how the exterior looks - IMO, the Gen4 might even look slightly better but I digress).

(Is it the most frugal choice to buy new? No, but it also wasn't mine to have someone total my last car and their insurance to give a nice payout. Besides, if we really want to talk frugal these days, you might as well consider transit and a Uber. Buying a car has never been the most effective use of money anyways - probably the fastest depreciating asset out there with little hope of return. Neither is it frugal to ignore getting a set for winter weather in Canada - it is simply dangerous. Doubly so as the stock Toyo's have been reported to have basically no traction even in light snow)

Honestly, I'm shocked posters here would be getting even the basic facts wrong, given how much previous discussion there's been about 17" tires including switching to the CC2'S specifically. The piling on to claim the bad experience is simply my mistake to deviate from the OEM tires is completely non-sensical, even from an objective point of view. To date, I'm the only one who has reported on the webs that the 17" tire/rim combo yields worse of a ride and worse fuel economy. Everyone else including quite a few on this forum have reported improved ride quality (even if some qualify it with just "slightly") and more than 10% increase in Mpg with the CC2'S specifically.

 

You have might have had good luck - and in any case, you do you - but in general, it's a pretty bad idea to overinflate tires to ~45 psi in hopes of getting better fuel economy. The numbers show that there is usually only a 1-2% improvement in MPG as the tires are simply not designed to yield more just by overflating them that high. Plus, the opposite of your experience is usually true, with much worse, uneven treadwear and higher safety risks. If there's any car myth that should die, it's that overinflating tires is a good idea to get better fuel economy. You would save more from avoiding to have to replace tires earlier or worse, causing an accident.

...I will leave it at this, since I'm honestly astonished that this discussion could devolve into attacks/judgements of character and such disorderly conduct, but are you the same person who wrote this?

Perhaps we should just keep the judgements and assumptions to ourselves.

 

(took a while before I could finally get this posted - new member restrictions and all that)

Guess I will try and see if it's matter of getting used to it and having done some safety calculations, reinflate up to 32F/30R instead of trying 28F/27R - but perhaps after having it inspected first (I do worry there is something wrong with the suspension itself, or as you suggested, the suspension pucks still being installed - though, technically, wouldn't it be quite obvious as the vehicle would be slightly raised? Or am I mistaking this with a different kind of suspension puck?)

It still seems quite paradoxical to me that the 19" rims with thin tires could in any way feel better, even at the same diameter and increased sidewall. I was almost half-tempted to switch back to them (though won't because of the mediocre tire performance, theoretically worse mileage, rare tire size, and very, very expensive OEM rims if they were to be damaged in any way). Perhaps it is the "new-ness" of the tires (though so were the Toyo's...) and the characteristics of the CC2's themselves with a different tread design - but very strange since most say that it is smooth ride versus a harsh one.

Also, perhaps I should clarify that by "ride quality", I mean almost exclusively the (suspension) feel in the seat (i.e. excluding noises as I don't find that to be an issue. Though, noise-wise it seems to be same as the Toyo's - as in I don't notice it, and still find the car in EV mode to be superior than even a Lexus with running engine. And when it's not in EV mode... does it really matter how the tires sound over the gas engine?).

It's the somewhat-always-violent shaking in the cabin that I find to be concerning - which was not really an issue on the 19" - and almost makes me feel like I'm damaging the car in some way going over even minor road perfections at low 30-40km/h speeds. Again, not an experience that I've had in a Civic hatch (which surely does not have a better suspension than a Prius? Common sense should imply it is equal if not slightly worse, and likely also shares the same small-car characteristics)

_____________

In case anyone later finds this useful: went down a pretty deep rabbit hole trying to find the front and rear axle load number to do the safety math.**

Like others, Toyota has gone minimalist and stopped listing the GAWR (gross axle weight rating) on the door placard, but surprisingly, it can't be found anywhere on official CA or US websites or manuals (or Google). It can't even be found on the Toyota JP site. We have to go all the way to Toyota Motor Europe to get the EU owner's manual to find it listed (later found out that the toyota.co.uk's PDF brochure also has it - but not on the website... Fun fact: there is absolutely no weight or load information - except for vehicle capacity weight - listed in the CA/US owner's manuals, even though you can find it on the respective websites).



On pg. 586, it lists the front-axle GAWR to be 1065kg (2348 lb) and 1030kg (2271 lb) on the rear-axle. Dividing it by two, we get just slightly below the 35F/33R load capacity with rating of 88 (i.e. 1190lb/1157lb) for the OEM 195/50R19 88H tires, at 1174lb/1135lb. The margin is quite low, at only 16lb/22lb front/rear, but it should still be acceptable as IIRC the max gross weight is usually inflated a bit. Yet, it probably explains the increased inflation recommendation going at Autobahn speeds, as well as why the 19" are more prone to blowouts.

This also shows that the 17" placard spec for 195/60R17 90H is indeed much higher, with a more normal (for Toyota in general) 149lb/144lb margin (load capacity is 1323lb/1279lb at 36F/35R). And if we go with 32F/30R at a load rating of 94 (1334lb/1290lb), we will recover almost exactly the same/slightly higher margin, with no need for any higher. (28F/27R on the other hand will match the margin of the 19").

These GAWR numbers from the EU manual should be accurate to the CA/US spec (you can't find the gross vehicle weight listed on the US website, but the CA website lists 2030kg - but I'm quite certain this is an error; it lists the same weight for all trims and the 40kg offset/error probably gives away what happened here*).

Though, strangely, the Toyota JP website lists the gross vehicle weight (車両総重量) a full 150kg lighter, at only 1845kg (for the PHEV). No idea why this is the case unless they're using special materials in their JDM Prius's or perhaps more likely, they're using a different standard to calculate the gross weight. According to definition, the number should include the "vehicle's chassis, body, engine, engine fluids, fuel, accessories, driver, passengers and cargo" - I guess there can be ambiguities in how you calculate passengers and cargo across different national standards.

I also found out from their JP brochures in the footnotes that you should subtract 20kg from the gross weight if using 17" rims and another 20kg without the panoramic sunroof.

(*Take the Canadian Toyota website's 2030kg number and subtracting 40kg yields exactly 1995kg, so probably this is the weight of the base model with 17" rims. The SE trim also doesn't come with a panoramic sunroof, so there's no reason why all trims should have the same weight - honestly concerning that manufacturers including Toyota can't be bothered to post accurate specs on their websites or even the manuals in CA/US. Guess it's maybe EU regulations that prevent Toyota from being sloppy in the European manuals).

(**This is a good resource, with multiple examples including a 2010 Prius, on how to properly calculate the right pressure and safety margins for alternate size tires: An Ex Rocket Man's Take On It: Understanding Your Tires.)

 

Nah, I actually compared quite intensely between the latest gen Camry and the Prius, and also had access through family to extensively test-drive one before/after delivery. The Camry's suspension feel is only slightly better - though Toyota also decided it was a good idea to equip this gen's with 18" and 19" wheels... (Perhaps next gen they will put on 21" wheels like on the latest Crown. Ridiculous)

The Prius still won me over with the better fuel efficiency, plenty of EV miles for city driving, and also just not having to listen to a running engine on quiet side roads. Yes, theoretically a pure EV with better suspension could have also satisfied these, but as we all know, Toyota's only EV - outside China - the bz4x sucks and the others all suffer from crazy depreciation if not other issues.

Don't regret my choice to get the Prius at all, only wish that the ride could feel a tad bit better. The main point of this post is just me being baffled that 17" tires could in any way feel worse than 19", at the same diameter (less 0.4") and increased sidewall. Just doesn't make any physics-sense to me, and I have never seen anyone else (including several here who made the same switch) who had similar experiences going from OEM 19" to 215/55r17 CrossClimate 2 tires.