Greetings fellow prius owners, I have been a long time reader of prius chat, and wanted to share my experiences with everyone on one of the best upgrades you can make for your car; the tires. Background: I drive a 2007 second generation, solid black, non-touring prius. There are no mods done to the car itself that affect driving, so this opinion is one comparative to stock settings. I live in the midwest, so I have driven in the harshest of Illinois winters along with the most searing hot of Missouri summers. I drive both aggressively and fuel efficiently as traffic/mood/bad drivers around me dicates. I also drive my gearheaded housemates 2002 BMW 530i, so I have first person experience in regards to "superior handling, etc etc" The stock Integrities had 28k miles on them before I made the wise investment of getting better tires. After upgrading to the new tires, I clearly understood how terrible those tires were. After about 20k miles, they were nearly all worn down, there was signs of cracking, high speed stability (65mph+) was all but non-existent, and they slipped constantly on wet and eventually even dry pavement. The reason that sent me over the edge was the slipping. It became a safety issue at that point, and with the harsh winter/road conditions that was to come, there was no way in hell I was gonna keep those tires. And the sweet weather deities LOVE to shower the midwest in heavy rain, especially this year, so wet weather performance was a big point of contention. After doing much research, and reading NYPRIUS's very well thought out posts on both the 195 and 205 size tires, I decided to go with the 205/60R15 Toyo Extensas. These are on the stock rims, and run at 42psi front, 40psi rear. Immediate Thoughts: I drive fairly aggressively when I want to, so the cornering and general stability at high speeds were easily noticeable. Plus, I could finally go in a straight line without having to microadjust the steering wheel every second. I can easily stroll through the city on major highways at 80mph without fearing that a gentle breeze will slam me into the siderail. Grip is outstanding comparative to stock, and wet weather performance is equally amazing. I can literally feel the tires pushing the water away and sticking to the pavement during heavy rains. Initially I took about a 5mpg hit, going from around 50 (if I drove conservatively) to 45mog 8,000miles later: Same amazing performance. After the break in period, my MPG has gone back up to 50+. Road noise is still low. I absolutely love these tires. I find it almost a crime that Toyota has allowed the 185 tire size to be on the second gen prius'. Fuel efficiency is a priority, however the cost to safety was too much for my tastes. Conclusions: I highly recommend these tires to anyone who has the stock integrities. Yes there are probably better tires, but if nothing else, get new tires, either in the 195 or 205 sizes. They are well worth the couple hundred dollars you'll spend, and will provide you with the peace of mind when driving in harsh weather/road conditions. Here is a photo album with some pictures of the tires and a recent drive around Saint Louis on the highways and roads. Photo Album - Imgur Potential Questions: Why not 205 vs 195? A: One of the biggest issues with driving where I live was the issue of going straight. This seems like a small quibble, but when nearly every other car is a chrysler 300 or bigger, they tend to push you around just from the air they displace. I make frequent trips up to Chicago from STL, so trucks are also abound. This was not an alignment issue, nor a road curvature issue. I wanted a larger size so that there was more surface contact, and therefore more grip to resist air flow/increased stability.