Tire size question

Yes, but your Speedometer and MPG calcs are going to be a bit off due to the different RPM's of the stock 185 size and your 195's.
I was going to go ths route myself, until I figured it was simpler to stay stock.
I bought the Michelin Energy Savers,
GREAT TIRE!!!.

 

The car handles noticeably better with 195/60 tires. Not a placebo effect. I would never go back to the narrow 185's. The speedometer over-read is nominal (about 2 MPH @ 70). I'll take that discrepancy any day for a better handling car.

 

I agree with roverguy, the 195/60 is the way to go. I went that route on my last set, and there is a definite improvement in handling and stability. As an added benefit, the 195/60 size opens up a lot more models of tires for you to choose from, as I think some popular cars like the Civic and the Focus use this size.

 

How about 195/65/r15 size. Narrow tread would be better for FE . I believe the stock size is 185/65/r15. H

 

Within a line of tires, 195/60 will have the same nominal tread width as a 195/65

The 195 is the nominal tire cross sectional width in mm and within a given line of tires, tread width tends to be a certain percentage of cross sectional width. The 60 and 65 have to do with the height of the tire cross section, not the width. 60 means the cross section is 60% as high as it is wide,

You will find some different tread widths between 195 width tires between different brands and models of tires.

 

65 is the width. H

 

Yes you are correct. So 65 would give more diameter.Is the Prius not running 185/65/r15. H

 

Here are some interesting specs on tire tread width and height (this is for the Michelin Hydroedge).

185/65: 5.8in tread width, 24.3 diameter
195/60: 6.3in tread width, 24.0 diameter
195/65: 6.1in tread width, 24.7 diameter

The 195/60 actually has a wider tread than the taller 195/65 tire.

 

nobody mentions 205 size tires. Im running 205-65-15, they most definitely fit and the car is a lot more stable. the car also rides a little higher which is nice for speed bumps etc.

 

205/60 is a good option and the revolutions per mile are very close to the stock 185/65. However, quite a few tire places will balk at installing a tire that size, even though it is well within spec for the stock Prius wheels.

 

205/60 are wide and the FE would suffer? H

 

Take a look on the sticker on the passenger door. That will tell you what should be on the car and any plus sizes that Toyota authorizes.
When dealing with any change in the width and aspect ration of the tire you may encounter the tire not fitting in the wheel well and it being too close to the suspension part etc.
Of course anything is possible.