The 2013 Toyota Prius liftback is the latest edition of the quintessential hybrid-electric car. It's the fourth model year for the current shape, first launched in 2010, and it's now the centerpiece of a whole lineup of vehicles called Prius, including the Prius V wagon, the Prius C subcompact hatchback, and the Prius Plug-In Hybrid, which adds a larger battery pack that can be plugged into the wall to recharge to the classic Prius model.

The plug-in Prius and the iconic standard Prius liftback are all but identical on the outside, with only a charging-port door on the right rear fender--and a handful of trim details--giving away the identity and the changes under the skin of the plug-in model.

As it has for four years, the Prius liftback achieves the highest EPA combined rating for gas mileage of any car sold in the U.S.: 50 mpg (51 mpg city, 48 mpg highway). That combined rating, in fact, is equaled by only one other car--and that's the subcompact Prius C, which does better in the city test cycle (53 mpg) but worse on the highway (47 mpg).

For the 2013 Toyota Prius liftback, the heart of its efficiency is the 1.8-liter four-cylinder engine and the Hybrid Synergy Drive system, which combines a pair of electric motor-generators into the electric equivalent of a continuously variable transmission. The motors can power the car on electricity alone (under light loads up to 30 mph), supplement the engine output with more torque, and of course recharge the battery under regenerative braking and on engine overrun.

Total output of the powertrain is 134 horsepower, with a 0-to-60-mph time of just under 10 seconds. You'll get a lot of engine howl if you floor it, though, which tends to encourage more gentle driving for better efficiency. Toyota has more experience than any other maker in blending regenerative braking with the standard friction brakes, and the combination works flawlessly and imperceptibly under most circumstances. The standard Prius liftback can, at best, eke out a mile or so under all-electric power (you can test it by putting the car into "EV" mode, which runs only on electricity at lower speeds until the 1.4-kilowatt-hour nickel-metal-hydride battery pack is depleted.

The Prius Plug-In Hybrid model swaps out that battery for a 4.2-kWh lithium-ion pack, which can be plugged into any wall socket to recharge in about 3 hours. Its usable energy is about three times greater, and the EPA rates it at 11 miles of electric range--though only 6 miles continuous, since the engine switches on to deliver the necessary power during part of an EPA test cycle.

That points out the frustrating aspect to the plug-in Prius: Its electric motor is so minimally powered that under many different types of real-world driving, the car can't deliver the needed power electrically. So its engine will switch on even if there's plenty of energy left in the battery. Toyota engineers argue that this is how you deliver the highest overall fuel efficiency, but for drivers who want the car to travel electricity for those 11 miles, it's disconcerting for the engine to switch on under more than the gentlest acceleration. Electric acceleration onto short uphill freeway on-ramps? Forget it. Like all plug-in hybrids, the real-world blended gas mileage across both modes depends hugely on how often the car is plugged in, how it's used, and at what speeds and temperatures it's driven.

The high roof and tail of the 2013 Prius shape contain a lot of interior volume: enough for the EPA to define it as a mid-size car. There's plenty of room for four adults, and five will fit with a bit of negotiation. Rear-seat legroom is boosted by hollowed-out front seat backs, though those seats have fairly skimpy padding. The split rear window, with a long, almost horizontal glass panel in the tailgate, and another vertical pane on the downturn, make the iconic Prius shape one of the most aerodynamic cars sold today--all in the aid of lowering drag at higher speeds to raise fuel economy.

Inside, the 2013 Prius is starting to look dated. Not only are there swathes of textured hard plastics everywhere, but the instruments are split into two areas. Conventional gauges are in a hooded binnacle behind the steering wheel, and then there's the Multi-Information Display at the top of the dashboard and toward the base of the windshield--which seems increasingly incoherent and primitive compared to newer hybrids and even newer Prius models. It contains a seemingly random array of diagrams, icons, and numeric readouts, and it adds to the potential confusion for first-time drivers unused to the continuously variable engine speed--when the engine behavior (and hence its noise) is completely divorced from acceleration and road speed.

The other aspect of the interior that sets a Prius liftback apart from other cars is the "flying buttress" central console, which swoops down from the top of the dash at a shallow angle that makes it much higher than any other family car's console. This gives it enough space underneath for an awkward-to-reach storage bin, but taller drivers will find the hard-plastic console cuts uncomfortably into their knee room.

Toyota's traditionally numb electric power steering is part of the Prius experience, along with handling than feels less capable than it actually is. The Prius actually responds fine to driver input, and corners capably; it just feels lifeless and numb through the steering wheel. Sports-car fans need not apply. Safety ratings are top-notch, however, and the Prius includes all the usual electronic safety systems and the usual quota of airbags. There's also the much-touted Intelligent Parking Assist system, which helps a driver parallel-park a Prius by controlling the steering wheel based on input from the car's cameras. Ford's system is better, frankly.

As before, the 2013 Toyota Prius offers four trim levels, confusingly named Two, Three, Four, and Five. (There IS a very stripped-down base Prius One trim level, but you can't buy it; the car is only offered to commercial fleets.) With the addition of the Prius C at under $20,000 to anchor the low end of an expanded Prius range, even the lowest-level Prius Two and Prius Three trims now start in the mid-twenties. And it's possible to price a Prius well above $30,000 by adding either the solar moonroof--whose photovoltaic cells power ventilation fans to pull hot air out of the cockpit on warm days--or the Technology Package.

Options include the Touch Tracer steering-wheel controls, one of the better implementations of pseudo-mouse technology we've seen on a car, along with things like LED headlamps, remote air conditioning, a navigation system, Bluetooth pairing, and more. For 2013, there's a new limited-edition Prius Persona Series model, with special paint colors, interior trim, and 17-inch alloy wheels.

The 2013 Toyota Prius liftback is the latest edition of the quintessential hybrid-electric car. It's the fourth model year for the current shape, first launched in 2010, and it's now the centerpiece of a whole lineup of vehicles called Prius, including the Prius V wagon, the Prius C subcompact hatchback, and the Prius Plug-In Hybrid, which adds a larger battery pack that can be plugged into the wall to recharge to the classic Prius model.

The plug-in Prius and the iconic standard Prius liftback are all but identical on the outside, with only a charging-port door on the right rear fender--and a handful of trim details--giving away the identity and the changes under the skin of the plug-in model.

As it has for four years, the Prius liftback achieves the highest EPA combined rating for gas mileage of any car sold in the U.S.: 50 mpg (51 mpg city, 48 mpg highway). That combined rating, in fact, is equaled by only one other car--and that's the subcompact Prius C, which does better in the city test cycle (53 mpg) but worse on the highway (47 mpg).

For the 2013 Toyota Prius liftback, the heart of its efficiency is the 1.8-liter four-cylinder engine and the Hybrid Synergy Drive system, which combines a pair of electric motor-generators into the electric equivalent of a continuously variable transmission. The motors can power the car on electricity alone (under light loads up to 30 mph), supplement the engine output with more torque, and of course recharge the battery under regenerative braking and on engine overrun.

Total output of the powertrain is 134 horsepower, with a 0-to-60-mph time of just under 10 seconds. You'll get a lot of engine howl if you floor it, though, which tends to encourage more gentle driving for better efficiency. Toyota has more experience than any other maker in blending regenerative braking with the standard friction brakes, and the combination works flawlessly and imperceptibly under most circumstances. The standard Prius liftback can, at best, eke out a mile or so under all-electric power (you can test it by putting the car into "EV" mode, which runs only on electricity at lower speeds until the 1.4-kilowatt-hour nickel-metal-hydride battery pack is depleted.

The Prius Plug-In Hybrid model swaps out that battery for a 4.2-kWh lithium-ion pack, which can be plugged into any wall socket to recharge in about 3 hours. Its usable energy is about three times greater, and the EPA rates it at 11 miles of electric range--though only 6 miles continuous, since the engine switches on to deliver the necessary power during part of an EPA test cycle.

That points out the frustrating aspect to the plug-in Prius: Its electric motor is so minimally powered that under many different types of real-world driving, the car can't deliver the needed power electrically. So its engine will switch on even if there's plenty of energy left in the battery. Toyota engineers argue that this is how you deliver the highest overall fuel efficiency, but for drivers who want the car to travel electricity for those 11 miles, it's disconcerting for the engine to switch on under more than the gentlest acceleration. Electric acceleration onto short uphill freeway on-ramps? Forget it. Like all plug-in hybrids, the real-world blended gas mileage across both modes depends hugely on how often the car is plugged in, how it's used, and at what speeds and temperatures it's driven.

The high roof and tail of the 2013 Prius shape contain a lot of interior volume: enough for the EPA to define it as a mid-size car. There's plenty of room for four adults, and five will fit with a bit of negotiation. Rear-seat legroom is boosted by hollowed-out front seat backs, though those seats have fairly skimpy padding. The split rear window, with a long, almost horizontal glass panel in the tailgate, and another vertical pane on the downturn, make the iconic Prius shape one of the most aerodynamic cars sold today--all in the aid of lowering drag at higher speeds to raise fuel economy.

Inside, the 2013 Prius is starting to look dated. Not only are there swathes of textured hard plastics everywhere, but the instruments are split into two areas. Conventional gauges are in a hooded binnacle behind the steering wheel, and then there's the Multi-Information Display at the top of the dashboard and toward the base of the windshield--which seems increasingly incoherent and primitive compared to newer hybrids and even newer Prius models. It contains a seemingly random array of diagrams, icons, and numeric readouts, and it adds to the potential confusion for first-time drivers unused to the continuously variable engine speed--when the engine behavior (and hence its noise) is completely divorced from acceleration and road speed.

The other aspect of the interior that sets a Prius liftback apart from other cars is the "flying buttress" central console, which swoops down from the top of the dash at a shallow angle that makes it much higher than any other family car's console. This gives it enough space underneath for an awkward-to-reach storage bin, but taller drivers will find the hard-plastic console cuts uncomfortably into their knee room.

Toyota's traditionally numb electric power steering is part of the Prius experience, along with handling than feels less capable than it actually is. The Prius actually responds fine to driver input, and corners capably; it just feels lifeless and numb through the steering wheel. Sports-car fans need not apply. Safety ratings are top-notch, however, and the Prius includes all the usual electronic safety systems and the usual quota of airbags. There's also the much-touted Intelligent Parking Assist system, which helps a driver parallel-park a Prius by controlling the steering wheel based on input from the car's cameras. Ford's system is better, frankly.

As before, the 2013 Toyota Prius offers four trim levels, confusingly named Two, Three, Four, and Five. (There IS a very stripped-down base Prius One trim level, but you can't buy it; the car is only offered to commercial fleets.) With the addition of the Prius C at under $20,000 to anchor the low end of an expanded Prius range, even the lowest-level Prius Two and Prius Three trims now start in the mid-twenties. And it's possible to price a Prius well above $30,000 by adding either the solar moonroof--whose photovoltaic cells power ventilation fans to pull hot air out of the cockpit on warm days--or the Technology Package.

Options include the Touch Tracer steering-wheel controls, one of the better implementations of pseudo-mouse technology we've seen on a car, along with things like LED headlamps, remote air conditioning, a navigation system, Bluetooth pairing, and more. For 2013, there's a new limited-edition Prius Persona Series model, with special paint colors, interior trim, and 17-inch alloy wheels.