The roads near our house are hilly and twisty. Push any car down a twisty mountain road and its tires will wear quickly. We don't baby this car just because it's a hybrid. All who live in this area are accustomed to lower gas mileage than EPA rating and lower than rated tire life, sometimes severely.

The MXV4 S8's lived most of their short lives at 40psi until my wife took over the car and neglected checking/refilling them. I, too, wondered how they could have lost so much pressure so quickly.