With its topnotch fuel efficiency, solar-powered ventilation system and various high tech features, Toyota‘s 50-mile-per-gallon Prius topped this year’s list of 10 greenest cars.

According to the Kelly Blue Book, the Prius remains the most fuel-efficient car in its class of hybrids, boasting 51 mpg city and 48 mpg highway. Aside from its hybrid powertrain technology, Prius was praised for its glass moonroof with a solar-powered ventilation system, voice-activated navigation and Dynamic Radar Cruise Control with Lane Keep Assist.

“To be considered for the green Top Ten, each vehicle was required to offer fuel economy and carbon dioxide emissions superior to the bulk of vehicles in its class and at the same time provide all the safety, creature comforts and driving enjoyment that would make it pleasant to own,” Kelley Blue Book said in its website.

This year’s list was largely dominated by last year’s collection, but also included two newcomers — the Volkswagen Golf TDI, one of the newest “clean diesels,” and the Chevrolet Tahoe Hybrid, which demonstrates SUV-like features that can co-exist with a hybrid powertrain.

Rounding up the top five are Honda Insight Hybrid (41 mpg), Ford Fusion Hybrid (39 mpg), Volkswagen Golf TDI (34 mpg) and MINI Cooper (32 mpg). Ranked sixth to tenth are the Ford Escape Hybrid (32 mpg), Honda Fit (31 mpg), BMW 335d (27 mpg), Toyota Highlander Hybrid (22 mpg) and Chevrolet Tahoe Hybrid (22 mpg).

The New York Times reported that Toyota will introduce a third-generation Prius in May in line with Toyota’s plan to sell a million hybrid cars in the next few years, from about 250,000 hybrids in 2008.