2009 Lexus LS 600h LPosted on February 24th, 2010
Hybrid technology gives flagship sedan a performance edge
By Nina Russin
Two years ago, Lexus introduced the LS 600h: a hybrid version of its flagship LS sedan. The technology is similar to the hybrid synergy drive in the Toyota Prius. But whereas Prius engineers focused exclusively on fuel economy, the Lexus team was more concerned with boosting power.
The hybrid powertrain in the Lexus 600h combines a 5-liter V-8 gasoline engine with two motor generators, yielding 438 system horsepower. The Lexus 600h accelerates from zero-to-sixty miles-per-hour in 5.5 seconds. A nickel-metal hydride battery pack recharges the electric motors.
Standard all-wheel drive automatically transfers engine power to the wheels with the best traction, enhancing the sedan’s four-season performance. The sedan has a 40/60 front-to-rear power split under normal conditions, mimicking rear-wheel drive. When the driver pushes the car, a limited slip differential can transfer up to seventy percent of engine power to the rear axle.
Three driving modes fine-tune the car’s performance for the driver’s needs. The hybrid mode maximizes fuel economy, while a power mode enhances acceleration. A snow mode minimizes wheel slippage on wet roads.
Long wheelbase adds legroom
This week I had a chance to test drive the Lexus 600h L: the long-wheelbase version of the sedan. The long wheelbase adds five inches of rear legroom, compared to the standard LS sedan.
Standard features are what one might expect from an ultra high luxury sedan costing over $100,000. All models come with a hard drive navigation system and backup camera, Bluetooth interface, voice command, and XM satellite radio. A nineteen speaker Mark Levinson audio system has sound quality comparable to high-end home setups.
Semi-aniline leather seats and an Alcantara headliner enhance the interior’s upscale appearance. Other standard amenities include heated and cooled front seats, heated rear seats, a heated steering wheel, push button start, and an electronic parking brake.
A premium option package adds power rear seats which recline up to 38 degrees, rear side airbags, an ultrasonic park assist system and Lexus Link. The rear seats can move fore and aft up to three inches. An advanced parking guidance system uses sonar sensors, the rear backup camera and the car’s electronic power steering system to guide the car into a parallel parking space ($4000).
Dynamic radar cruise control allows the driver to preset a following distance from the car in front, enhancing the sedan’s fuel economy in heavy traffic. The same optional also adds pre-collision, which can help to detect pedestrians in the vehicle’s path ($2850).
Test drive in the mountains
As impressive as its comfort and convenience features are, I was more interested in the hybrid sedan’s performance. I wanted to determine how effectively the hybrid powertrain enhanced fuel economy, and also wanted to experience the all-wheel drive system on some challenging mountain roads.
Like the Toyota Prius, the Lexus 600h is a true hybrid, capable of operating in pure electric or gasoline electric modes. EPA fuel economy is 20/22 mpg. While that doesn’t seem like an impressive figure, it’s pretty good for a 5360 pound car with a top speed of 130 miles per hour. My average fuel economy was considerably higher than the EPA estimates: about 24.7 miles-per-gallon on the highway.
With over 13 years of experience under their belts, Toyota and Lexus engineers have developed a masterful command of the hybrid lexicon. The technology is seamless, and essentially invisible to the driver. Except for the engine shutting off at idle, the LS 600h’s performance is virtually indistinguishable from a conventional car.
Because electric motors develop peak torque at extremely low engine speeds, the sedan has the ability to accelerate extremely hard off the line. During my test drive, I happened to come upon a driver in a Jaguar XK, two-plus-two sports car. The Lexus was able to match the Jaguar off the line, despite weighing close to 2000 pounds more.
Engineers tuned the electric power steering to provide plenty of assist at low speeds with firmer response on the highway. Because of its high curb weight, on-center response is not as good as it might be. I was able to simulate an emergency lane change, but was well aware of the weight transfer.
The sedan’s braking system consists of ventilated rotors on all four wheels, with four piston calipers up front and two piston calipers in the rear. Lexus uses a brake-by-wire setup in lieu of hydraulic components. The electronic system is lighter and more responsive than conventional brakes, but the brakes tend to grab during a hard stop. The hybrid system recaptures braking energy to recharge the battery pack.
A continuously variable transmission gives the sedan seamless acceleration with no shift shock. I was impressed with the standard air suspension: it provides a cloud-like ride on flat roads, but stiffens up as necessary to keep the car flat in the corners. I was able to move through some challenging corkscrew turns at very high speeds.
Visibility is pretty good around the car, though there are some blind spots to the rear. Over-the-shoulder visibility is quite good to both sides. The standard rearview camera makes it easier to park the long wheelbase sedan.
As with all Lexus products, the 600h sedan is notable for its dead quiet interior. Rear seat passengers will have no problems conversing with those in front.
Power seat adjustments should make most drivers and passengers comfortable. I had plenty of lower back support for my three-hour drive into the mountains. Unfortunately, Phoenix weather was too warm to test out the seat heaters or heated steering wheel.
I found controls on the center stack and steering wheel easy to use, and had no problems seeing the gauges in a variety of lighting conditions. The graphics for the standard navigation system are easy to follow.
The long wheelbase gives passengers in back almost as much legroom as those in front. Vents behind the center console circulate air through the back of the cabin. Because of the car’s high floor tunnel, the back of the sedan can only hold two adults.
The sedan’s biggest drawback, aside from the price tag, is its extremely small trunk. Engineers located the battery pack between the rear seats and the trunk, making it impossible to create a pass-through for extending the cargo floor. The trunk may hold a golf bag or two but it will not hold a bicycle.
The Lexus LS 600h comes standard with eight airbags, antilock braking, electronic stability control, and LED headlamps. Standard adaptive lighting automatically swivels the headlamps according to steering input, to illuminate corners of the road. Keyless access allows the driver to unlock the car without removing the key fob from his pocket.
Base price on the Lexus LS 600h L is $105,885, not including an $825 delivery charge. The high-performance high luxury sedan is on display at Lexus dealerships nationwide.
Likes: A hybrid sedan with good fuel economy, low emissions, and exceptional power. The long wheelbase gives second-row passengers almost as much legroom as those in the front of the car.
Dislikes: Small trunk.
Model: LS 600h L
Base price: $105,885
As tested: $113,560
Horsepower: 389 @ 6400 rpm
Torque: 385 lbs.-ft. @ 4000 rpm
Zero-to-sixty: 5.5 seconds
Antilock brakes: Standard
Side curtain airbags: Standard
First aid kit: Standard
Bicycle friendly: No
Fuel economy: 20/22 mpg city/highway
Comments: The manufacturer recommends using 91 octane fuel.
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