Afraid the 2010's 17 in wheels 45 tires might ruin the ride

I like them, I like them a lot.
I don't particularly like the mileage hit from the extra width but I like the wheels and the tighter handling they will bring.

I doubt we will see them here.

 

UK Prius stock wheels are 195/55 R16.

The smaller sidewalls on the 45% profile tyres will not flex as much. That means more of the work of handling bumps will have to be done by the suspension itself - the ride and grip are really the product of the suspension combined with the tyre. I would hope that the suspension would be altered to match the larger diameter tyres. (The Touring model in North America currently has different, softer suspension compared to the Base model.)

However, when cornering, the stiffer sidewalls of the lower-profile tyres should support the car better and reduce body roll.

It does seem odd to only offer 15" or 17" options, with no 16" option, though.

 

On the bright side, there'll always be an aftermarket waiting out there for the new wheel/tire set if you don't like 'em.

 

i hear your point, but i too, with patsparks like the looks of the 17' wheels....check that, i love the looks of it. some truck tires have a bit more of a sidewall height, but i have no idea about this specific size.

my 06 cadillac sts had "magnetic ride control" so maybe toyota can incorporate a self tuning suspension in their premium line. just food for thought? or maybe an option of sport/street/touring? so the driver has control of their suspension harshness based on real world road conditions

 

and to add 1 more bit of anecdotal marketing research for the Toyota team:

I traded to a HyCam due to highway stability issues. I'm hoping the improvements made to the suspension will be enough to overcome the Gen 2 issues, but I'll continue to have concerns till I see some objective driving tests. I like the looks, but would take the MPG hit and get 17" tires only if I thought it would help the car stick to a straight line on the highway and in cross winds. Anyone care to comment on that issue?

The bulk of my driving is likely to be on rutted, pothole filled Houston streets. This was another area the Gen 2 was not great at; adequate, but still economy car jarring compared to the HyCam. Other people have commented that the low profile tires on these 17" tires may not be what finally gets put on the final production car. My vote is for a softer ride. Perhaps someone at the next special invite could ask about (i) the final tire choices, (ii) whether there will be different suspension components or other design changes on the high end cars, (iii) whether the bias will be towards sport or comfort, and (iv) whether there will be any reason people can't switch between 15" and 17" for all models (someone asked this on another thread and was never answered).

If I want fun, I'll buy a Mini. I don't want to be punished with lower MPG and harsher ride if I choose to get LED headlights or adaptive cruise control (of course, for $4,500, that may also be an unlikely choice, but I'll save that for another thread ).

 

Mike,

Unlike the current Touring Edition's "tuned suspension" (larger diameter front and rear sway bars, softer rear springs, different rear shocks), I believe that the suspension of the 2010 with 17" wheels will not be altered.

When I go to the NYC show, I'll ask the Toyota reps and also look under the cars.

* * * * * * * *

Personally, I have no problems trading a softer ride for better handling. A lot of us already do that with the common increase of tire pressures to 42 front/40 rear or more.

 

The chief engineer said the 17" is more fun to drive.

 

Probably, but if I'm silly enough to want to spend $4,500 for cruise control and/or $1,500 for LED headlights, then why also make $1,500 17" wheels a forced add-on, especially if there are no other design differences to accommodate the 17" wheels? Why not have high end 15" wheels instead, with a 17" option? Differences in packages based on design or manufacturing issues, like leather, headlights, nav, or sunroofs, make sense. Everything else should be mix and match as much as possible, like the Scion.

I sympathize with the difficult marketing/packaging decisions that go into this, especially in this market. I would think Toyota has to be concerned about putting luxury car pricing on an economy car. I'm not sure headlines about a $36,000 Prius are going to help sell the car.

It seems useful for people here to put out their own ideas on the subject of tires, packages and options, so that Toyota gets some marketing feedback while there is still time to make adjustments. May not help this year, but 2011 is coming soon!

 

It will be this size and profile of tyre, to match the rolling circumference of the 15" wheel as closely as possible. In fact, if Tideland's quoted sizes are correct, a closer match would be an even wider tyre with the same profile ratio, 225/45 R17 (0.03% smaller, rather than 1.45% smaller). Going to a higher ratio you end up with a narrower tyre than the 15" wheel, a 185/55 R17 (and the sidewall is about the same size as the 45% ratio anyway).

If you go for a larger sidewall on the 17" rim, the torque calculations have to be redone, as the actual force applied to the road surface is the torque applied to the centre of the wheel divided by the rolling radius of the wheel+tyre. Larger tyre, smaller force for the same torque. It would need a different final reduction gear ratio to compensate, which would probably necessitate a different transaxle casting, as the centre of the gear would need to be in a different position.

The new base wheel/tyre combination is about 2% bigger in rolling circumference than the 'Iconic' Prius' 185/55 R15.

 

Tideland,
The only wheels on the current Prius in Australia is the 15 inch fitted with 195/60 15 Michelin Energy XM1 tyres. This is on both the base model and the iTech, the only 2 options we get.

I would like to fit a Touring spoiler to mine just to make it a little more different. I think the touring spoiler would make the car look a little longer and visually make the car look lower in profile. I might even get 17 inch wheels at the next tyre change as long as I can get LRR tyres to suit. I might go to 185/50 17 or something like that as long as I can get narrow enough wheels, to gain back some of the lost economy of the bigger wheels.

 

pat - correct me if i'm wrong, but i THINK the low profile "50 series" 185 is still a bit wider than the "60 series" 185 designation. but this is an interesting thought.

the lower profile would make it handle a bit better. imho, the 185 tires are a bit small for the prius.

 

I've posted this elsewhere, but I'm willing to trade my 15" 2010 wheels when my car arrives for your 17". Keep me in mind when you get your Platinum pack Prius.

 

No, 185 is 185mm wide regardless of the profile.
a 185 width would have less sidewall flex than a 205 or 215 wide tyre. In fact on stock rims I think 215 wide tyres would feel wallowy. (is that a word?) I believe the Prius has 6 inch rims.
Drifters use narrow tyres on wide rims to increase response and speed break-away. It stiffens the tyres. I had 205 wide tyres on 7 inch rims to give good steering response on the front of my race car while I had 225s on the back for better acceleration traction coming out of corners. I had a class restriction to 7 inch rims.

I'll add, I have seen posts from one owner who fitted 175 wide tyres to his Prius!

 

expect 2010 prius to be firmer than old one, even with 15" tires and considerably so... but i wouldnt worry too much as recent toyota's pretty much have best-in-class mix of suspension comfort and handling... all recent cars have been really well tuned - yaris, auris, avensis (talking about european models)...