It's new car. Please do not smoke in the car. No pet allowed. Prius is a power-split or series-parallel (full) hybrid, sometimes referred to as a combined hybrid, a vehicle that can be propelled by gasoline and/or electric power. Wind resistance is reduced by a drag coefficient of 0.25 (0.29 for 2000 model) with a Kammback design to reduce air resistance. Lower rolling-resistance tires are used to reduce road friction. An electric water pump eliminates serpentine belts. In the US and Canada, a vacuum flask is used to store hot coolant when the vehicle is powered off for reuse so as to reduce warm-up time. The Prius engine makes use of the Atkinson cycle.