After totaling my 2010 Prius II, not Two (only 2010 used uppercase roman numerals for model designation), a week ago I'm thinking about replacing it with a 2012 Prius 5. Probably gonna swap out the 17s for my 2010's 15s. Just wondering if there's and downside besides the looks which I don't really care about. I've read that changing the Prius 2 to 17s throws off the mileage/odometer and I'm mostly just wondering if the opposite is true for the 5. Thanks.
Yes the swap will change things. In motorcycling, we run into this issue a lot when we change gearing/sprocket sizes on chain drive bikes. Sometimes, it's drastic change and an electronic correction box that feeds the speedometer is needed. Anyway, here's a calculator for wheel sizes I've used before: Speedometer Calibration / Tire Size Change Calculator
You're odometer & speedometer will only be affected if you're changing the overall diameter of the tire. Here is a pretty good chart which organizes tire size-specs for each wheel size under tire diameter sizes: Tire Size Chart So, if the OEM spec is 175/65R14 (a 23" diameter tire) or 175/65R15 (a 24" diameter tire) you should choose a size that corresponds to the same diameter. You will also notice an impact on your gas mileage if you're changing the overall weight of the wheel & tire. Less rotating mass equates to improved efficiency.
That and the dif in price/lifespan are the reasons I want to switch to the 15s. I drive like 70-80k a year. If I'm reading that chart right the oem 17s are actually an inch smaller then oem 15s. Kinda of annoying but I'll probably still switch. Might have to check into having it adjusted though. Edit: or getting a smaller 15" tire I guess
