Wife's 2008 Prius with 46K miles. Just filled it up - 32MPG. This has been going on for a few months. We replaced the 12V battery, based on recommendations here. Still horrible mileage. The dealer charged us $110 to check the car out, said nothing is wrong. I am convinced the batteries are bad. I watch the "video game" and the engine is charging the batteries ALL THE TIME. What recourse do I have? The dealer says there is nothing wrong. As I said, replaced the 12V. Driving habits have not changed. Tires are inflated to (our) spec and fine.