In fact, many people don't realize the GS 450h is a hybrid unless they see the hybrid badges on the car's exterior.
Technology, handling, styling and quiet ride are all noteworthy in this middle-of-the-Lexus-line sedan that slots between the larger Lexus LS and entry ES sedans.
The 2013 GS hybrid is the first car to combine rear-wheel drive/front-engine layout with an efficient Atkinson cycle V-6.
Buyers can even get a distinctive bamboo-covered steeringwheeland interior trim on the GS hybrid, in a nod to environmental concerns about using renewable resources.
The Lexus GS is a recommended buy of Consumer Reports magazine, which finds its reliability above average.
The GS 450h is the top model of the GS line in both horsepower and price. Starting manufacturer's suggested retail price, including destination charge, is $60,360 for the 338-horsepower GS hybrid; this does not include navigation system, trunk cargo net or front passenger seat memory.
By comparison, the base, 2013 GS 350, which is powered solely by a 306-horspower V-6, has a starting retail price of $48,150.
Competitors to the GS hybrid are the major luxury brands with hybrid powertrains. For example, the 2013 Mercedes-Benz E400h is a luxury, mid-size sedan with 302-horsepower, gasoline-electric hybrid power. Starting MSRP, including destination charge, is $57,625. Infiniti's 2013 M35h hybrid starts at $55,655 and has a 360-horsepower V-6 mated to an onboard electric motor system.
None of these luxury hybrids is a plug-in. Rather, drivers generate electricity while driving, and it is stored in the onboard battery pack. In the GS 450h, the battery pack is the older-style nickel metal-hydride. Battery packs in the M35h and E400h are the newer lithium ion.
The GS hybrid is tops among luxury branded hybrid sedans in fuel mileage, according to the U.S. government. It is rated at 29 miles per gallon in city driving and 34 mpg on the highway.
These numbers, which are a 35 percent increase from the previous GS hybrid, are not far-fetched. The test car, with uplevel 18-inchwheels, easily averaged 28.4 mpg in driving that was mostly in the city and included constant use of air conditioning.
This translated into a single-tank range of nearly 500 miles.
All the driver did to achieve the mileage was activate "eco" mode, which changed throttle mapping and made other adjustments to conserve fuel. It is one of five selectable modes on the car.
The Infiniti M35h fuel economy rating by the government is 27/32 mpg, and the Mercedes E400h is rated at 24/30 mpg.
The most memorable part of driving the GS 450h is how quiet the ride is — conversations can be held in nearly hushed tones inside — and how smoothly power comes on.
Virtually all transitions among engine, the two electric motors and the battery pack were seamless in the tester. Indeed, if a driver didn't notice the word "ready" in green in the instrument cluster after pushing the start button, the lack of engine sound and engine vibration could make it seem as if the GS 450h hadn't turned on.
In eco mode, power came on gradually and steadily. But in sport-plus mode, throttle response was quick and engine sounds were prominent.
In just 5.6 seconds, according to Lexus, the GS hybrid can go from 0 to 60 miles per hour.
The V-6 is 3.5 liters, which is the same displacement as the engines in the E400h and M35h. But only the GS has an Atkinson cycle V-6, which is designed for fuel efficiency, and it's mated to a fuel-conserving continuously variable transmission (CVT) that sounds and acts mostly like a regular automatic.
In the test GS 450h, passengers did not hear engine droning, as they sometimes do in other hybrids that have CVTs, until the driver demanded hard acceleration.
The 2013 GS 450h received a major makeover from its predecessor. There's a new underlying platform with a wider track, which helps provide a sportier driving experience. Lexus also makes greater use of high-strength steel in the 2013 GS, which allowed a tauter body and new suspension design.
The test GS 450h surprised with its lack of body roll on long sweeping curves taken at high speeds. Steering response was good, particularly in sport-plus mode. Impressively, at railroad track crossings, the test GS 450h kept most bumps away from passengers. There was no noticeable wind noise.
On 90-plus-degree days, the GS 450h's ventilated front seats worked well and quickly.
Rear seat cushions were long and gave decent thigh support. Three adults in back, however, sit closely, and rear passengers sit by thick rear window pillars. Rear legroom of 36.3 inches and rear headroom of 37.8 inches are acceptable but not expansive.
The flat trunk is nicely finished and has more space than expected: 13.2 cubic feet.
2013 Lexus GS 450hBASE PRICE: $59,450.
PRICE AS TESTED: $70,280.
TYPE: Front-engine, rear-wheel drive, five-passenger, luxury, gasoline-electric hybrid, mid-size sedan.
ENGINE: 3.5-liter, four cam V-6 with VVT-i mated to a two-electric-motor system and nickel-metal hydride battery pack.
MILEAGE: 29 mpg (city), 34 mpg (highway).
TOP SPEED: 131 mph.
OPTIONS: Luxury package with heated rear seats (includes three-zone, automatic climate control, 18-inch, alloywheels, bi-light-emitting-diode headlamps with adaptive front lighting, 18-way, power front seats, rear-door manual sunshades, heated wood steeringwheeland outboard rear seats, pre-collision system with driver attention monitor) $9,760; carpeted trunk mat $105; cargo net $64.