The 100-mpg Prius You Can Recharge at Home

Image Gallery The idea of recharging a car at home may sound strange, but 100 mpg will probably help you get over that real quick. Plug-in hybrids offer the best of gasoline-electric hybrids and all-electric cars: the ability to drive in pure electric mode (thus zero gas used), a gas engine to fall back on when needed and the ability to recharge at home. TOYOTA

On the outside, the Toyota Prius I’m driving looks about the same as any Prius you’d see on any given day. Aside from the auto-show graphics on the body, the only hint of something unusual on this Prius is the second fuel door on the rear flank of the passenger side. Pop it open and instead of a gas cap, there’s an electrical outlet. This particular Prius is more than just a gasoline-electric hybrid — it’s a plug-in hybrid. The one I’m driving is one of several that Toyota is using to test this promising and advanced technology.

A plug-in hybrid runs solely on electric power for longer periods than a typical hybrid, thanks to extra batteries. And like a typical hybrid, a plug-in taps the gasoline-electric hybrid powertrain when driving distances exceed the electric-only range. Toyota is currently testing a small fleet of plug-in Prius that have an all-electric range of seven miles. Seven miles may not sound like much, but it’s enough for short commutes or errands. While driving on that electric power, a plug-in Prius can achieve the fuel economy equivalent of 100 miles per gallon or more. A conventional Prius gets about 48 mpg in city driving.

More Batteries and a Power Cord

Toyota’s Hybrid Synergy Drive system allows its hybrid vehicles to operate on electric power (via batteries and an electric motor), gasoline power (via a small internal combustion engine) or a combination of the two when both are needed. The plug-in version has a second nickel-metal hydride battery pack, which powers the extended electric range unique to the plug-in. The additional batteries fit where the spare tire normally goes. Additionally, Toyota revised the hybrid system’s computer controls to allow the plug-in to operate on all-electric power longer and at higher speeds than in a conventional Prius.

When it’s time to recharge, a simple power cord is connected to the Prius and plugged into a standard 110-volt outlet (the kind we all have in our homes and garages). A full charge will require three to four hours, or just 1 to 1.5 hours if a 220-volt outlet is available.