This review is for the benefit of other hypermilers considering replacement tires for their Prius. At 30k miles I replaced the OEM Goodyear Integrity tires with the same size Continental ContiPro Contact in 185/65x15. The Integrities were LOUD over anything but the absolute smoothest pavement and the Contis are an improvement in both noise and ride harshness at the same inflation pressure. Driven repeatedly over the same route my fuel mileage has decreased approx 5% or 3-4 mpg using both the MFD and ScanguageII. The last several tanks on the well-worn Goodyears were at 66-67 mpg and the first three tanks on the Contis have been 63 mpg. The odo and speedo have changed slightly compared to GPS so I think larger tire diameter accounts for about 1% of the mileage drop. It is possible that winter fuel blend might account for some of the drop and I will update this review if I find that to be the case.
I can't comment on handling or traction other than to say it's completely adequate...'cuz it's a Prius and I drive it like, well, a Prius. I will say that noise level and ride harshness is improved compared to the Integrities.
High praise for TireRack. $45/each on sale and shipped promptly.