Introduced as a 2007, the hybrid GS gets minor changes for 2008 that include revised gauges, more noticeable hybrid badges and different trims. Back then, it earned the distinction of becoming the first mass-production rear-wheel drive luxury hybrid car.

Power comes from a combination of sources, including a 3.5 liter V6 used elsewhere in the Lexus range. In this application, it is bolstered by an electric motor. This powertrain is dubbed Lexus Hybrid Drive and is rated at a combined 340 horsepower at 6,400 rpm and 267 lb-ft of torque at 4,800 rpm. The gas engine by itself is rated at 292 hp at 6,400 rpm and the electric motor at 134 kW. This power flows through an electronically controlled Continuously Variable Transmission to the rear wheels.

Fuel economy is rated at 22 mpg in the city cycle, with the hybrid returning 25 mpg on the highway, as estimated by the EPA. The conventional, gas GS350 returns 19 mpg in the city, and 27 mpg on the highway, respectively, so the hybrid's added weight actually hurts it on the open road.

Apart from the hybrid mechanicals and extra computers, the hybrid GS gets more standard features compared to the GS350, which is expected considering the hybrid commands a $10,000 premium. Buyers do get standard 18-inch wheels and tires instead of a 17-inch wheel and tire package, active suspension is standard fare also, and not at all available on the 350, a power rear sunshade is standard as are ventilated front seats, and bigger front brakes. Hybrid buyers also get standard adaptive headlights, high-pressure headlight washers, a back-up camera, parking assist and a rolling code remote as opposed to a rolling code key.

The GS450h is also a little quicker to 60mph.

The more noteworthy options include Lexus' Active Power Stabilizer Suspension System with run-flat tires, a radar-enforced Pre-Collision System and dynamic cruise control, different style of 18-inch wheels, a choice of Sirius or XM satellite radios, a voice-activated navigation system and Mark Levinson premium surround sound audio system, among other stand-alone options.