Equipped with the second generation Lexus Hybrid Drive system.

Yes, the Lexus 2013 GS 450h delivers 338 total system horsepower, while achieving 31 combined city/highway mpg. Arriving in dealerships in May, the 2013 GS 450h will have a base MSRP of $58,950, unchanged from the model it replaces.

While testing for a week I got 35 MPG in eco mode

GS 450h
The Lexus 2013 GS 450h will complete the GS lineup when it joins the recently launched GS 350 and GS 350 F SPORT at Lexus dealerships in May. With a total system power output of 338 horsepower, the GS 450h not only has the power of a V8, but also exceeds most V6 engines in fuel economy with best-in-class EPA estimated ratings of 29 mpg city, 34 mpg highway, and 31 mpg combined. The GS 450h is certified as a Super-Ultra Low Emissions Vehicle (SULEV).

Like the GS 350, the new GS hybrid also features Lexus Drive Mode Select. In addition to the Normal, Eco, Sport S, Sport S+ modes available on the GS 350, the GS 450h adds an EV mode, which allows the driver to travel a short distance at low speed using only the hybrid battery pack.