- Outstanding mileage

 - Ultralow emissions

 - Generous amount of interior room

 - Hatchback utility

 - Reasonable price

 - Excellent build quality

- Less power than other midsize sedans

- Real-world fuel economy doesn't live up to EPA estimates

The Prius wasn't the first hybrid car on the market in the U.S., but with four doors, a sizable trunk and room for four, it was the first such vehicle to offer the practicality of a typical economy car along with the outstanding fuel mileage of a hybrid. The second-generation model, introduced in 2004, delivers all that and more, with an even larger interior, hatchback utility and a hybrid drivetrain that's more powerful and cleaner than the previous version.

Apart from its high-tech drivetrain, the Prius offers comfortable accommodations for four adults. It's a little smaller than most midsize sedans, but even tall passengers have enough room in the rear seats. Top-notch interior materials and a unique design give the cabin an alternative look and feel, but all the amenities you would expect are there. The Prius features an innovative automatic climate control system that runs entirely on electricity. This means the A/C will continue to cool even when the gas engine is not running, such as at a stoplight. It also features a humidity sensor and smart programming so the A/C compressor runs only when it is necessary. The benefit is that you can leave it in auto-mode year round without worry of wasting any energy.

The Prius is available as a four-door hatchback only, in one well-appointed trim level. The standard features list includes power windows, locks and mirrors; automatic climate control; a tilt steering wheel with audio and climate controls; a six-speaker CD stereo; cruise control; trip computer; and 15-inch aluminum wheels. Options like a DVD-based navigation system, Bluetooth hands-free phone technology and a nine-speaker JBL premium audio system with a six-disc CD changer are also available, along with leather seating and xenon headlights. The available Smart Key system allows you to lock/unlock the doors and start the car with the key safely in your pocket or purse. The optional voice command system permits voice control of features ranging from temperature adjustment to Bluetooth cell phone dialing.

All models come standard with four-wheel antilock brakes with BrakeAssist and traction control. Electronic stability control and side-impact/side curtain airbags are optional. Government crash tests resulted in a four-star (out of five) rating for everything but the driver in the frontal-impact test, which earned five stars.

Materials quality is impressive, and the overall look is upscale. The gauge cluster is positioned toward the center of the dashboard, but the display is clear and easy to see. The optional touchscreen DVD-based navigation system features a backup camera display and can be voice-operated.

As you'd expect, the Prius is no speed demon (zero to 60 mph in about 10.4 seconds), but when it comes to the kind of daily driving that most drivers encounter, there's more than enough power to get around. The continuously variable transmission (CVT) takes some getting used to since it doesn't shift gears, but it does make the best use of the hybrid drivetrain's power. Cabin noise is minimal, and the suspension is comfortably soft without feeling too floaty.

Solomon Technologies Inc., of Tarpon Springs, Fla., filed the complaint last month against Toyota Motor Corp.

Solomon provides propulsion systems for marine applications and motors for land vehicles and machinery. The Solomon propulsion system also regenerates electricity, according to a company statement.

The company alleges in a federal lawsuit that hybrid technology in the Toyota Prius and Toyota Highlander gasoline-electric hybrids infringes on a Solomon patent.

"The investigation is an important next step in our continuing prosecution of the infringement by Toyota," Solomon President Peter W. DeVecchis, Jr. said. "As I have noted previously, we believe that the ITC's streamlined administrative process, as well as the technical depth of the ITC staff, will be helpful in expediting and supporting our claims."

According to Solomon's complaint, inventor Jonathan Edwards got a patent in 1991 for a "dual-input, infinite-speed integral motor and transmission device" and assigned the patent to Town Creek Industries Inc.

Town Creek and Toyota held discussions about the patent but never reached an agreement, according to the company. Solomon subsequently acquired Town Creek and claims to now own the patent for the "dual input, infinite speed integral motor."

An administrative law judge will hold a hearing on the claim and issue a determination which is subject to ITC review.

The trade commission has authority to block imports of products that the commission finds infringe on U.S. patents. Toyota could be prohibited from importing the hybrid system into the U.S. which include drive systems for the Prius and Highlander models.

Toyota had no comment.