Powered by a 3.5-liter V-6 sporting an Atkinson Cycle valve timing, 13:1 compression ratio, direct injection, and mid-port intake tumble generator, the GS 450h features a battery of fuel-saving techniques before you get to the hybrid side of the drivetrain.
That hybrid side is what boosts the 3.5-liter's rating to deserve the "450h" badge, combining an electric motor with a nickel-metal hydride battery pack. A power-split device uses planetary gears to combine power from both the engine and the electric motor as needed. The combo is good for 338 net horsepower and 5.6 seconds to 60 mph--not shabby for a hybrid, and definitely in the mix with the Infiniti M35 Hybrid's 350 horsepower and 6.1-second 0-60 times. The M Hybrid rates 32 mpg highway, but the 2013 GS 450h hasn't claimed a rating as yet.
The new GS hybrid rides inside the skin and bones of the new GS sedan, complete with its crisp edges and generally pleasing lines. Lexus says the upgrade to the new platform, along with use of upgraded suspension bits common to the GS line, make the 2013 GS 450h a solid performer in the corners. Lexus Dynamic Handling System, a fancy name for four-wheel steering, helps the car rotate at low speeds and remain stable at higher speeds.
For the full details and specs, catch the official press release on page two.