So why 175/65R15??

Corrected in my list. It's still noteworthy that they list that tire at lower RPM than any other 175/65/15 unless 856 is just a dyslexic typo for 865.

865 175/65/15 Yokohama AVID ENVigor
856 175/65/15 LRR Continental ContiProContact### (mislisted on tirerack.com as 844)

 

Does the suspension upgrade on the 16" mean it should have a smoother ride? Also, in Canada we have only three trims: Standard, Technology, and Premium Packages. The premium package comes with 16" alloy wheels for about the same price as your c 4 with tire upgrade.

 

All else being equal, the 16 inch wheels would give a little rougher ride but it might not be enough for you to notice the difference.

 

From the Edmonds review they say the 16" wheels have a much larger turning radius than the 15" wheels. What other advantages / disadvantages are there between the two?

 

they make 14inch for Prius C in Japan. I would like to have 14 inch.

 

I notice on the Toyota site that the 15" alloys are only available for the model III and IV (standard on the IV and optional on the III). Does anybody know if there's some physical reason why these alloy wheels wouldn't fit on the I and II models?

 

They should fit on all levels, if not someone
should not have been an engineer.

 

it is simply how they sell them, only attached to those models..

 

With tires, the smaller the width, the more is the MPG. A regular 175 tire should give more MPG than a low-rolling-resistance 185 tire.

tires-easy.com has 25 different selections for this tire size:

175/65R15 tires on tires-easy.com

 

No, but if you do replace them you need to get the steering adjusted.

The reason the 16" turning radius is larger is that they limit the steering so that the tires don't rub on the car.

 

It really is quite simple. If you drive straight ahead, the inner and outer edge of the tire tread travel the same distance. If you are turning (or navigating a winding road), the inner and outer tire tread are travelling different distances. This means you are always scrubbing the tire tread when you are not driving straight ahead. The wider the tire, the greater this effect! Not only does this increase tread wear, it reduces your MPG! If you bought your C to enjoy fuel efficiency, don't put wider tires on it!

______
Prius c III, moon-roof, absolutely red

 

There is also evidence in theory that a wider tire will lower RR up to a point but it gets really screwy because CdA changes as well. I gave up trying to second guess the manufacture and I will just stick with 195/65/15s. lol

 

Not sure where you got this but it's incorrect. Only the IV's with the 16" alloys have the turning-circle-limited steering set up. Nothing would need changing for the 15" alloys on the I, II or III models.


ron

 

If you need more proof, go out to a parking lot (where it's very quite), roll down your window and listen to the difference in noise level when you are going straight versus turning. Assuming your wheel alignment is okay (which will also affect MPG), the difference in noise is due to tread scrubbing. I won't argue as to whether the effect is small or large. You are listening to increased friction.

Try it...

 

Whats the mpg on a prius w/ 17 " factory wheels....same as 15'' ??? just wondering.