LAS VEGAS -- The Toyota Prius, a household name that has come to define hybrid cars for nearly two decades, was reborn here Tuesday night with the introduction of a bigger, more fuel-efficient model for 2016.

Toyota didn’t release powertrain details on the redesigned and re-engineered Prius (those are expected ahead of the Tokyo Motor Show in October), but the company promised the 2016 version would be lighter, 10 percent more fuel efficient than its predecessor and -- rare for virtually any hybrid -- fun to drive.

The latest Prius, Toyota pledged in a statement, "will offer best-in-class fuel economy among vehicles without a plug."

The fuel efficiency gains resulted from smaller and lighter components in the hybrid system, denser batteries that pack more energy and a more efficient internal combustion engine, Toyota said.

The outgoing 2015 Prius, with a 1.8-liter engine, is rated at 51 mpg/city, 48 mpg/highway and 50 mpg combined.

To mark the event, Toyota hoisted a new fourth-generation Prius into the night sky on cables from the top of the Linq hotel here, while the band Atlas Genius played for a crowd of journalists, dealers and company brass.