So why 175/65R15??

Perhaps because it is a subcompact and weights only 2,500 lbs. That's all it is needed to stop rather quickly.

Don't worry, more LRR tires in that size will become available especially if the sales skyrocket as expected.

When Gen II Prius came out in 2004, 185/65R15 tires were non-existence. LRR choices for that size are now plenty.

 

If the Prius C is popular the choice will be there by the time your tires wear out.

I wonder about advantages vs disadvantages of the 16" vs 15" wheels. I know about stiffer ride and sharper handling for the 16", but what about rolling resistance and wet pavement/snow worthiness of the wider tires? Has anyone ever gone to wider, lower-profile wheels/tires and noticed a difference in gas mileage?

 

The 16" tire is 20mm wider (195 vs. 175). The recommended tire pressure difference is 3-4 psi.

15" Front: 35 psi Rear: 33 psi
16" Front: 32 psi Rear: 29 psi

 

these can be fitted on the gen2 prius?
nice.. i want 175 instead of 195

 

They won't fit in Gen II. ODO and speedometer will be off.

 

Yes the 185/65R15s of the gen II seem like a better choice with so many options available. I'm sure it was to save a few ounces of gasoline from lower rr with the smaller footprint. In japan they even sell smaller 14s.

 

Is the bolt pattern actually different?
Of course the odometer and speedometer will be off, and corrections will be needed there. It hasn't stopped people from going smaller or larger in the name of personalization.

Somewhat related, is the rim width of the 16" alloys known? They are sharp looking and EPS would be nice, but I'd want a narrower tire for daily driving.

 

I'm sure the OEM tire on the c will be LRR rated and even if it is not, the width difference should be enough to work at least as well as a super LRR 185/65/15. Extra tire width really is a mpg killer. We see it time and again when someone upsizes to wider tires and larger wheels.

Like stated above, by the time you need new tires there should be plenty of choices available. We already have the Ecopia EP422 and Assurance Fuel Max tires available.

 

will the odo be the only reason or the bolts don't fit? I don't care about the odo

 

Nope, Prius c wheels have 4 bolts instead of 5. Tire load index is 123 lbs lower as well.

 

don't worry about the bolts, buy tires and put them on the existing Gen II rims.

Oh, and it's the odometer & speedometer that are affected just to be clear.

If you want a 175 that fits the Gen II without throwing off the speedometer just get 175/65/15 LRR Continental ContiProContact which is 844 RPM. Exactly what the Gen II needs. Just don't confuse it with the 20 other tires continental makes with nearly identical names.

175/65/15 Bridgestone Ecopia EP422 would read 3% too fast as would 175/65/15 Yokohama AVID ENVigor, 175/65/15 Goodyear Assurance Fuelmax, any basically any other 175/65/15 on the market.

All-Season Tires sorted by Revs per mile.
875 185/60/15 Hankook Optimo H727

869 175/65/15 Bridgestone Ecopia EP422
??? 175/65/15 Goodyear Assurance Fuelmax
866 175/65/15 General Alimax HP
865 175/65/15 Yokohama AVID ENVigor

858 195/60/15 Hankook Optimo H727
856 175/65/15 LRR Continental ContiProContact
855 185/65/15 Goodyear Assurance Fuel Max
852 185/65/15 Bridgestone Ecopia EP422
851 185/65/15 Michelin Energy Saver A/S w/ Green X
850 185/65/15 Yokohama AVID ENVigor
848 185/65/15 Continental ProContact with eco Plus

843 185/65/15 General Alimax HP
842 185/65/15 LRR Continental ContiProContact

 

To add to the above informative post keep in mind that the OEM 185/65/15 Integrity tire was rated at 855 revs/mile. While this would be an ideal number to shoot for, it causes the speedometer to read approx. 2mph too fast. The 844 revs/mile tire mentioned above may help correct the speedometer error.

I would, however, veryify that the revs/mile info for the ContiProContact is true. It seems rather low compared to the rest of the tires in that size. Also do not confuse it with the ProContact EcoPlus tire which is generally considered better.

*EDIT*

I just looked up the Continental ContiProContact and the 175/65/15 is rated at 856 revs/mile according to the manufacture data sheet located here:

http://www.conti-online.com/generat...i_pro_contact/contiprocontact_en,tabNr=4.html

 

I am running Hankook 205/55/16 eco tyres at 831 TMP on my UK Prius "OEM Bridgestone 195/55/16 at 855 TPM" and have gained MPG (figures to follow later) speedo still over reads by approx 1.5%.

 

Mine either but with the only other choices being non-LRR I would likely just go with something we know works. Wayne Gerdes uses the Fuel Max tire.

 

16 inch is standard on the eu prius
we don't have the 15
I need 175 on 16 ?
and I care more for the odo them for the speedo I drive a prius not a sports car.

 

Why put shorter tires on your car, that is just like changing to a lower gear ratio and would hurt economy.

The dumb Smart car uses even smaller 175/55/15s on the rear and baby 155/60/15s on the front!

 

The Prius doesn't use a fixed gear system like a standard transmission vehicle so the effect of the shorter tire is not the same. The eCVT will adjust RPM as needed for peak efficiency regardless of tire diameter.

 

less contact better mpg