DETROIT • Toyota Motor Corp. is looking to keep the Prius in its spot as the top-selling hybrid in the U.S. with the next generation of the iconic fuel-sipper.

The highly anticipated 2010 Prius unveiled Monday at the North American International Auto Show in Detroit gets an average of 50 miles to the gallon. That's a 4 mpg improvement over the current model, which already is the most fuel-efficient vehicle ranked by the Environmental Protection Agency.

The third-generation gas-electric Prius has a more aerodynamic design, but its exterior is easily recognizable as a Prius. Toyota says pricing will be released before the midsize sedan goes on sale in late spring.

Automakers are using the Detroit auto show to spotlight more fuel-efficient vehicles. The new Prius debuted a day after Honda unveiled its next-generation hybrid, the 2010 Insight, which will arrive in U.S. showrooms in April and is expected to compete head-on with the Prius.

Honda Motor Co. said the Insight will have a lower price than the Civic Hybrid, which has a base price of $23,650. The 2009 version of the Prius starts at $22,000.

Also Sunday, Toyota's Lexus luxury arm unveiled a new hybrid sedan called the HS250h and Ford Motor Co. showed off the 2010 Fusion Hybrid that will get 41 city mpg and 36 mpg on highways. The Fusion was unveiled in November and goes on sale this spring.

The debuts come as hybrid sales have tumbled. Gas-electric cars sold briskly as gas prices peaked last summer but have since come down sharply as fuel prices collapsed to their lowest levels in six years. But Toyota says it expects gas prices to stabilize at a higher level, boosting long-term demand for hybrids.

"Since Prius was first introduced, the consumer demographic has shifted from an early adopter to a mainstream shopper," Bob Carter, Toyota Division group vice president and general manager, told reporters at a news conference.

Carter said the 2010 Prius will go on sale in the U.S. and Japan in late spring, followed shortly by Canada and other countries. The automaker hopes to sell 180,000 new Prius vehicles in the U.S. in 2010, the first full calendar year they're on sale.

The new Prius is getting a larger and more powerful 1.8-liter four-cylinder engine. Toyota says the bigger engine helps improve fuel economy on the highway.

An optional solar-powered ventilation system uses an electrically powered air circulation fan that doesn't need the engine to work. It prevents the interior air temperature from rising while the vehicle is parked. The ventilation system can be remotely operated, so drivers can adjust the interior temperature before getting inside.

Also at the Auto Show

• General Motors Corp. named LG Chem Ltd. of South Korea as the lithium-ion battery supplier for its Chevrolet Volt electric car and announced the seeds of what could become a battery development and manufacturing center in Michigan. LG Chem will make the battery cells in Korea and ship them to the U.S., where they will be assembled into packs at a GM factory.

• Ford Motor Co.'s luxury Lincoln line debuted a new concept car, the Lincoln C. In a switch for Lincoln, the C is a small car designed to attract customers in urban centers who are looking for luxury in a compact package.

• California startup Fisker Automotive debuted a production version of its plug-in Fisker Karma, vowing to sell 15,000 of the sporty luxury hybrids. The Karma, which has solar panels on the roof, will have a starting price of $87,900 when it rolls off the assembly line in October at a factory in Finland.

The Associated Press