Purchased the Continental ProContact EcoPlus the Fall of 2012 after much research at Tire Rack and Consumer Reports. Could have gotten a few thousand more miles out of the OE Yokohama AVID S33D but winter (rain) was coming. Hated the S33's as they did nothing well except help get good gas mileage and was only going to get 40,000 miles out of them. Immediately the EcoPlus were quieter, smoother, and with great wet grip but the mileage dropped from 52mpg to 47 or 48 and I was disappointed. I knew winter might be a factor and old worn down tires roll easier than new tires but I was still surprised. Now that Spring has arrived and the tires have 6K on them my mileage is back up. Just returned from a 451 mile trip to Santa Rosa and Fort Ross and the trip meter is showing 54.3mpg. That includes freeway, urban, and coastal driving. I could not be happier. Air pressures are at the correct settings for the Prius, 35 front, 33 rear. I don't think there is much advantage in higher pressures compared with the disadvantages; harsh ride, less contact patch, increased braking distance, wandering on the highway, and wearing out the center of the tread. I used to be the manager of a busy tire store and from the tire manufactures seminars I learned that hard over-inflated tires are more susceptible to punctures. A tire that is rock hard will puncture much more easily than one that has a little give to it. Imagine a balloon that is very full versus one that is not so full. The full one pops much more easily. Go with the car manufactures recommendation. They have worked with the tire manufactures to give you the best tire pressures for your vehicle in regard to safety, longevity, handling, comfort, and overall performance. The engineers for the cars and the tires know better than you. I love my Prius and my almost new but broken-in EcoPlus tires. These are at the top of my list when I need to buy new tires for my Subaru Baja.