P225/45/17 = p195/65/15

I don't see a concern with the ABS and I'm guessing they'd rather deal with a speedo error of less than 1mph at 65 than they would with a tire that is 1.18" wider than the 15".

 

I'm curious about this too, but installing spacers would avoid the rubbing issue if 225 proves to be too wide.

 

Crank you wheel all the way to the left and right, and measure clearance around each front tire at the two extremes.

 

IMHO 225 is much too wide a tire, my guess is that mpg will really drop due to the added weight of the tire along with more rolling resistance due to the wider footprint.

Like NoMoShocks said, crank the wheel lock to lock and measure to confirm.

How come Toyota uses 215 instead of 225? See first paragraph.

For a vehicle such as a Prius, it's mission in life is to achieve the highest mpg. Honestly, the 17's I think were more of a "fashion statement" and a way to give the car a more sporty appeal to attract a larger audience. Just my 2 cents....

 

The 225's are about 4/10" wider than the 215's. Possibly noticble but not significantly so. The 215/17's already look good and anything wider would kill FE