YPSILANTI, Mich. (AP) — Toyota has two important vehicles coming in 2015: the next-generation Prius hybrid and the company's first hydrogen fuel cell car.

Satoshi Ogiso, a top Toyota engineer who helped develop the original Prius 20 years ago, said Wednesday that the new Prius will get significantly better fuel economy than its current 50 miles per gallon. It will have an advanced battery, motor and gas engine combination that is smaller, lighter and cheaper than the current version.

Ogiso wouldn't reveal the fuel economy, but he's hoping to at least match the 10-percent gains Toyota has gotten in the last three generations of Priuses. A 10 percent gain would get the Prius to 55 mpg in combined city and highway driving.

"The challenge to continue to improve at this rate, to beat your own record, becomes very difficult but makes it all the more motivating," Ogiso told media at an event near Detroit. "I can tell you that we are very motivated to beat our record."

The new Prius will ride on a new, lower chassis to improve its handling and aerodynamics. It will also have a nicer interior. Ogiso wouldn't say how much it might cost, but a less expensive hybrid system could help bring down the Prius's $24,000 price tag.

Toyota hopes the revamped Prius will help it reach its goal of selling 5 million hybrids in the U.S. by 2016. As of July, the company had sold more than 2 million Toyota and Lexus hybrids, including 1.4 million Prius compact cars, Prius C subcompacts and Prius V wagons.

Bob Carter, Toyota's senior vice president of automotive operations in the U.S., said its hybrids have come a long way since the Prius debuted in the U.S. in 2000. Just over 5,500 Prius hybrids were sold that year; last year, the company sold 236,000 Prius family vehicles.

"Arguably, Prius is more than a car. It's become a pop culture icon," Carter said.

Carter added that even as the company introduces other technologies, including hydrogen fuel cell and electric cars, hybrids will remain at the core of the company's offerings for at least another 50 years.

"You can take any fuel efficient technology and extend the range and make it even more efficient with a hybrid," he said.

Ogiso said more details about the hydrogen fuel cell car will come early next year. So far, there is only one other commercially available hydrogen fuel cell car in the U.S.: Honda's FCX Clarity, which is leased in limited numbers in Southern California.

Zero-emission fuel cell cars are not likely to be big sellers until there are more hydrogen fueling stations on U.S. roads. But Ogiso said Toyota is committed to the technology and expects to sell "tens of thousands" of them through 2030.