The next generation of Toyota's venerable hybrid hatchback will officially debut September 8 at an event in Las Vegas, right on schedule with previous reports that the new car would begin production in late 2015. The standard 2016 Toyota Prius hybrid is expected to debut first, with the plug-in variant to follow in early 2016.

The fourth-generation Prius is significant for many reasons, chiefly that it will be the first Toyota vehicle to ride on a new modular platform called Toyota New Global Architecture (TNGA). This will help the new car be approximately 20 percent lighter than before. It will also use a new gas-electric hybrid system, with efficiency said to rise at least 15 percent over the current Prius hybrid, which is rated at 50 mpg combined by the EPA. That means that a 60 mpg rating is a distinct possibility for the new 2016 Toyota Prius, which may switch to more expensive lithium-ion batteries to replace the heavier and less efficient nickel metal hydride batteries used in the current car.

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Though the new car's design won't be a significant departure from the outgoing Prius' aerodynamic hatchback shape, a slightly edgier design inspired by the Toyota C-HR concept is reportedly in store.The interior will look to move upscale with higher-quality materials and a different dashboard design, according to spy photos. Look for the 2016 Prius to also offer more active safety features than the outgoing car, as part of Toyota's initiative to bundle these systems in its Toyota Safety Sense packages.

After the 2016 Toyota Prius makes its debut to the world, production will likely begin in a few months, with the car going on sale in the U.S. either at the end of 2015 or the beginning of 2016. Watch this space for more updates on the next-gen hybrid as we learn more information.