With a new Toyota Prius on the horizon, rumors abound as to what the next-generation of the world's best-selling hybrid will offer when it's unveiled late next year.

Some changes are a given: Better fuel efficiency, an improved interior, a revised yet familiar shape.

Others, such as all-wheel drive, looked less likely--but Toyota engineers are still considering this addition, according to Automotive News.

"I think we will possibly do it", said senior managing officer in charge of powertrain development, Koei Saga.

All-wheel drive wouldn't be the car's main drivetrain layout--the next Prius will still be a front-wheel drive car.

MORE: All-New 2015 Toyota Prius: What We Know So Far

But Toyota's next-generation hybrid drivetrain will be used across a wide range of vehicles and in different applications. AWD is useful technology that could be applied across several of those future hybrid models, making it a viable option on the Prius too.

Saga did not expand beyond those comments, but confirmed that the next-gen Prius would come with both nickel-metal hydride and lithium-ion battery options.

The latter is likely to give drivers a longer range on battery power alone--at a cost. The nickel pack would remain as a low-cost entry point to the Prius range.

MORE: 2015 Toyota Prius Launch Pushed Back Six Months: Report

Toyota is targeting a 10-percent economy improvement for the new car, which would peg it at 55 mpg on the EPA test cycle--though Saga suggests it could be higher than people are expecting.

"I think we will come up with a fuel economy that will surprise everyone," he told Automotive News.

He also says that Toyota will add "unprecedented" new concepts in its larger hybrid vehicles.

Whatever the final specifications, Prius buyers will have to wait a little longer than expected to get their hands on the car.

Originally due next Spring, Toyota has pushed the launch back six months, to December 2015, while the company performs extra tweaks to aspects of the car.


Follow GreenCarReports on FacebookTwitter and Google+