The 2012 Hyundai Sonata Hybrid isn't the first environmentally friendly family sedan on the market. It is, however, a solid first effort from the Korean automaker, with stylish good looks, a long list of standard features and several technological firsts lurking beneath its hood.

As for those powertrain innovations, the Hyundai-designed hybrid system uses a lithium-polymer battery pack that's both lighter and more compact than the nickel-metal hydride batteries powering comparable models from other carmakers. The electric motor has also been placed between the four-cylinder gasoline engine and a traditional six-speed automatic transmission, which makes for a more familiar driving experience compared to the droning engine note of competitors using a continuously variable automatic transmission (CVT).

This all sounds good in theory. But in practice, Hyundai's hybrid system falls short of expectations. First and foremost, we've found that it falls far short of those lofty EPA mpg estimates. It's thrifty to be sure, but not as much as is promised. (Hyundai later revised its estimates for the car, going from 35 mpg city/40 mpg highway to 34 mpg city/39 mpg highway.) The Sonata Hybrid also leaves something to be desired in terms of refinement, with acceleration at low speeds marred by mild shuddering and lurching. Brake feel is also a bit odd.

Competitors like the Ford Fusion Hybrid and Toyota Camry Hybrid do not suffer in such ways. The big price difference between the Sonata Hybrid and the entry-level Sonata -- which is rated at a very impressive 35 mpg on the highway -- also makes the Hybrid a tough sell from a bottom-line-oriented point of view.

In total, the 2012 Hyundai Sonata Hybrid is a decent choice in a fuel-sipping family sedan, but it needs some work before it receives the sort of recommendation we give the non-hybrid Sonata.

The 2012 Hyundai Sonata Hybrid is a midsize sedan that's offered in a single well-equipped trim level.

Standard equipment includes 16-inch alloy wheels, automatic headlights, LED running lights, foglamps, heated mirrors, keyless ignition/entry, dual-zone automatic climate control, an eight-way power driver seat, cruise control, a tilt-and-telescoping steering wheel, Bluetooth, Hyundai's BlueLink emergency communications, and a six-speaker sound system with CD player, satellite radio, an iPod/USB audio interface and an auxiliary audio jack.

There are just two option packages available. The Leather package bundles leather upholstery, heated front and rear seats, a leather-wrapped steering wheel and shift knob, and an auto-dimming rearview mirror. The Ultimate package starts with everything from the Leather package and adds 17-inch alloy wheels, a panoramic sunroof, a touchscreen navigation system, a rearview camera and a nine-speaker Infinity sound system with HD radio.

The 2012 Hyundai Sonata Hybrid is powered by a 2.4-liter four-cylinder gasoline engine generating 166 horsepower and 154 pound-feet of torque that is paired with an electric motor making 40 hp and 151 lb-ft. Combined, the two power units are good for 206 hp and 193 lb-ft of torque. A six-speed automatic with manual shift control is the only transmission offered.

In Edmunds performance testing, the Sonata Hybrid accelerated from zero to 60 mph in 8.7 seconds, which is reasonably quick for a hybrid. The EPA estimates Sonata Hybrid fuel economy at 34 mpg city/39 mpg highway and 36 combined. However, in Edmunds fuel economy testing of both the Sonata Hybrid and the mechanically similar Kia Optima Hybrid, we found that both fall a couple miles per gallon short of these estimates.

Standard safety features on the 2012 Hyundai Sonata Hybrid include antilock brakes, stability control, traction control, front side-impact airbags, full-length side curtain airbags and active front head restraints. Hyundai's BlueLink emergency communications system is also standard.

In government safety tests, the Sonata Hybrid earned a top five-star rating for overall crash protection, with four out of five stars given for overall frontal protection and five stars for overall side protection. In Insurance Institute for Highway Safety testing, the 2012 Hyundai Sonata earned a top rating of "Good" for frontal-offset, side-impact and roof-strength protection.

In Edmunds brake testing, the Sonata Hybrid came to a stop from 60 mph in 126 feet, an average result for the class.

On the road, the 2012 Hyundai Sonata Hybrid offers a nice combination of nimble handling and a smooth, composed ride quality. There's plenty of power on tap, whether you're accelerating away from a stop sign or pulling out to pass on a two-lane road. Where this hybrid powertrain disappoints, however, is in low-speed driving or quickly changing traffic conditions. In these situations, the Sonata Hybrid often shudders and lurches while deciding which gear it wants. It is similarly indecisive under braking, as the transition between electronic regenerative braking (which helps recharge the battery pack) and mechanical braking is clumsy and unpredictable. Almost all hybrids exhibit some quirkiness, but the Sonata Hybrid's acceleration and braking is the quirkiest of the bunch.

Not surprisingly, the Sonata Hybrid's passenger cabin looks and feels very similar to its traditionally powered sibling. The interior is equally handsome and controls are straightforward and intuitive, both with and without the touchscreen interface that comes as part of the Ultimate option package. The gauge cluster, which is one of the most notable things that sets the interior apart from that of the non-hybrid model, includes a separate LCD display meant to encourage more fuel-efficient driving.

Front seats are comfortable and supportive. The backseat offers plenty of room for two adults, though taller passengers will find headroom in short supply. All hybrid sedans lose a good bit of trunk space to the hybrid system's battery pack, and the Sonata Hybrid is no exception, with just 10.7 cubic feet of cargo room. The regular Sonata, for comparison, has 16.4 cubic feet.