so the stock 15's are 195/65/15 and the 17's are 215/45/17. according to tire size calculations, this would result in a 1.4% increase in speed vs the speedo. are Prius V's ecu's tuned for these tires? i have a Prius II and am thinking now i need to get 225/45/17's to make sure my speedo is correct. please chime in
I'm not sure the accuracy of the speedometer is predictable in advance. My speedo was dead-on accurate when I bought the car in April. But the wheel alignment was so bad that we ruined two tires. Toyota gave me four new tires of the exact same size and brand as the OEM tires in August, and now my speedo reads 4 mph slow. Go figure.
