185/65R15 vs. 185/55R15 The OEM tire size for my 2009 Prius Base is 185/65/R15 I don't have the money to buy larger rims and tires like I really want to, however I need new tires. I can go a bit longer on them, but they will need to be replaced soon. And since I have to get them anyway, why not upgrade to something better! Has anyone tried a tire with a smaller sidewall to improve handling and turn-in? I was looking at 185/55 R15's on tirerack.com and they are about the same price as the factory OEM size replacements. Has anyone tried using a tire with a smaller sidewall? I'm rolling over on the sidewall while taking sharp curves, and accelerating on the on ramps as I drive. I know that the smaller size will change my speedometer reading, but I don't really care about that. I just wonder if someone has tried it, and did it work?