As a popular hybrid icon, the Prius has no equal. The Prius combines a roomy interior with a five-door aerodynamic body to create a shape that has come to define the Prius. Beneath the skin, Toyota's proprietary Hybrid Synergy Drive(R) integrates a 98-bhp 1.8L inline-4 with an 80-hp electric motor for seamless operation. In 2012, a Plug-in Hybrid version of the Prius joined the lineup. The Plug-in model replaces the standard Nickel-Metal Hydride battery with a larger Lithium-ion battery. The larger battery allows electric-only driving for about 11 miles at speeds up to 62 mph. After the charge is depleted, the Plug-in model behaves identically to the standard model. The Plug-in battery can be fully charged in 3 hours at 120V, or in 1.5 hours using an external 240V charger. Fuel economy performance for hybrids and plug-in hybrids depends heavily on driving habits, speeds and distances. The EPA rates the standard Prius at 51/48 (city/hwy). The Prius Plug-in is expected to be rated at over 87 MPGe. The plug-in model will only be available in 15 states. Toyota will expand availability to all other states in 2013.