Opting for the high-end Touring version of the Prius brings wider wheels and tires and a tighter suspension than the car's base version. This gives it better handling and braking, so it got through our avoidance maneuver three mph faster. It also stopped about 10 feet shorter from 60 mph. The main performance drawback is lower mpg: 42 vs. 44. However, the edge in performance could also give drivers an extra margin of safety. We think that's worth the extra money.