larger tire install

I think you are going to hear a bit of tire/fender liner noise as they make contact everytime you drive over a significant bump. I bought a 16 inch aftermarket wheel (42 mm offset) and stuck a 205/55 16 tire on the car. They fill the wheel well and have helped the car become more linear down the road. Fuel mileage is about the same, but the car handles better.

My winter tires are 195/65 15s and they match the 205/55 16 tire's diameter, 25 inches. A 205/65 15 will bump that diameter another half inch to 25.5" , so you may be at or beyond the size limit. For comparison, the 185/65 15 Integrity tire has a 24.4 inch diameter.

Maybe someone has tried a 205/65 15 and can tell if it really fits. I have my doubts. A 205/65 15 is a tall tire and may be a little softer riding, but it will have slightly more lazy turn in. Not sure you're goint to like that aspect.

And a larger diameter tire will slow your speedometer a bit. At an indicated 60 mph, for example, you might really be traveling 62 or 63. A good GPS will allow you to compare speedometer indicated vs. actual. Speedometers have been known to be off by a % or two, anyway.

 

I went to BFG G-Force Sport radials, and it transformed the car, in both wet and dry handling and traction. I fitted 205-60 15s to the stock wheels. My only complaint is that they are noisy at city speeds, quiet on the highway, and I took about a 5 mpg hit overall. The BFGs weigh 5 lbs. per wheel more than the OEM Integrities, but the difference in handling is worth every Lb., and lost mpg. I still get 43-44 in 80% freeway, 20% city driving. Check them out. The Goodyear Fuelmax wasn't available when I got the BFGs. After 35,000 miles, the wear is negligable, and I rotate front/rear at 10K miles, and run 40/38 tp. No fender clearance problems. I used the 60 instead of 65 because the diameter was loser to the OEM diameter. Good luck!

BTW these are summer tires, I didn't notice you are from Vermont, not sunny California where I live. There is a G-Force Super Sport A/S H/V all season, rated for snow, available too, but I've never used them.

 

Increasing the road friction by installing fatter tires will increase your Prius's fuel consumption, so you would want to do this WHY ? ?

If, as a consequence, the tire and the fender occasionally 'hold hands' it will be like hitting the brake without any regenerative effect, and it'll sound, every time you hit a bump in the road, like you or your car has a 'Flatulance problem' to anyone :scared: who rides along with you.

The idea has No Upside for a Toyota Prius, and it'll cost you money :doh: you could put to better use.

 

For winter (and we have a lot here!) I bought a set of 15" alloys from Tire Rack and mounted the 205/65 R15 Bridgestone Blizzaks I bought last winter for my 1985 Mercedes S-Class . While they do fill the wheel well they don't rub on the fender liners. Mileage has taken a hit of about 5 mpg but that has been the only downside. And in addition to the much better grip and handling with the Blizzaks, I know my 17" G-III-V rims and tires will be clean and unmarked once spring finally arrives here in SW Michigan.