The LS 600h L is smooth, quiet and stable at any speed, so much so, that there is practically no sensation of speed at all. The car feels under-stressed at normal highway speeds, with a huge reserve of speed and passing power.
Lexus designed the LS 600h to provide performance equivalent to V10 and V12 engines. Powered by the combination of a new 5.0-liter V8 and two new-generation electric motor/generators, the LS 600h readily attains a top speed of 135 mph, at which point an electronic limiter gently intervenes and slowly backs the car down to 130 mph.
At 120 mph, the tach reads just 3000 rpm, 1000 rpm below its torque peak, with the red line set at 6500. Because of the torque of the electric motor, 0 to 60 can be attained in 5.5 seconds, even in a car that weighs 5049 pounds. That's pretty quick.
The engineers at Toyota/Lexus can configure their Hybrid Synergy Drive for high mileage, high performance, or any combination of the two. In the LS 600h L, the system is biased toward performance. Midrange acceleration, in particular, is enhanced. The LS 600h L accelerates from 50 to 70 mph in 3.5 seconds.
Unlike a V10 or V12-powered luxury car, the LS 600h is EPA-rated to deliver 21 combined mpg, something more akin to a V6 powered mid-size sedan.
The hybrid drive system uses two powerful electric motors and a newly developed battery pack that is lighter and stores more electricity than previous systems. The system is capable of driving the car in electric only mode, or with a combination of gas engine and electric motor. The battery system consists of 288-volt DC Nickel Metal Hydride pack located behind the rear seat. In the trunk is a 12-volt auxiliary battery to power the audio system, navigation and lighting. The electric motors, MG1 and MG2, perform specific functions. Each can operate as both a motor and generator, although MG1 is used as a starter motor and provides no drive force. The engine-driven generator, MG1, can charge the battery pack or provide additional power to the drive motor, MG2, as needed.
Even though the hybrid is equipped with regenerative brakes, which recharge the battery as the brakes are applied, brake feel is typical of a standard car equipped with strong disc brakes, an impressive engineering achievement.
The LS 600h is the first North American hybrid that can operate in EV Mode, in which the vehicle will stay in electric-only mode at speeds below 25 mph for about a half mile. This feature might be useful to glide into the garage silently if you get home late, or get to a gas station if you ran out of fuel or maybe for use in stop-and-go commuter traffic.
On the road, the LS 600h feels like a rear-wheel-drive car, but is actually all-wheel drive. A computer mixes torque from the V8 and electric power source, feeding through a continuously variable transmission to achieve a balance between front and rear wheels. We noticed no hunting between front and rear, no sense of sorting from wheel-to-wheel as the car passes over different surfaces. There is none of the torque steer that accompanies high-horsepower front-wheel-drive cars, which can be detected in the front-wheel-drive Lexus RX 400h SUV. With the LS 600h L, peg the throttle and acceleration is smooth and linear, with an uncanny absence of drama. Using the tachometer, we were able to discern the moment when the electric motor assist kicked in, but only under full throttle. To the average driver, the hybrid system would be largely unnoticed.
The reduction in noise and vibration is a benefit from the air springs, which can be computer controlled for ride height, and have no metal parts to transmit noise.
As we drove at high speeds on Toyota's 10-mile oval test track, we had to remind ourselves that this is a SULEV, a Super Ultra Low Emissions Vehicle, with substantially cleaner emissions than vehicles with a conventional engine, and exhaust cleaner than the ambient air in some major cities.
The interior may be roomy, but from behind the wheel, the LS 600h feels like a smaller car. Especially at low speeds, steering is light and responsive, and the turning radius is surprisingly short for a car in this class. So much so, in fact, that the car lends itself to spirited driving on winding roads. Pavement dips, cracks and surface variations can be heard, but generally not felt, during cornering exercises. Especially with the optional active stabilizer, the air suspension offers the predictable handling of a rear-wheel drive car, maintaining a stable posture with minimum pitch or roll.
A BMW 7 Series sedan offers sharper handling, but its larger wheels and lower-profile tires let more road noise through to the cabin and more vibration to the wheel. With the optional active stabilizer package, the LS 600h L seems to deliver BMW-like control and handling, with less noise or vibration.
Active safety is enhanced by advanced electronics: Steering is electronically controlled, so it can offer a wide variation of ratios depending on speed and throttle conditions. The electronic power steering system partners with the vehicle dynamics integrated management system (VDIM), making minor adjustments to the front wheel angle for improved stability when roads become challenging. So in many ways, VDIM is a performance-enhancing system.
VDIM is also a safety system, monitoring input from the brakes, stability control sensors, steering wheel, throttle and engine torque. The system can actually anticipate the onset of a skid or slide. Using a combination of selective braking, throttle and steering control, the system can correct driver misjudgments in a manner essentially transparent to the operator. We tested VDIM extensively at the Toyota Proving Grounds by intentionally overdriving into corners, entering slaloms at impossible speeds, and speeding toward obstacles until they became unavoidable. We found that the degree to which VDIM can correct gross operator error is uncanny. It's a system we wish could be on every car.
On the LS 600h L there are other innovative safety systems that could be life-saving. One is the Advanced Pre-Collision System (APCS). It can detect pedestrians in the vehicle's path using two small cameras and millimeter-wave radar. A driver monitor system, mounted inside on the steering column, actually checks the driver's face. If the camera sees that the driver is not looking directly ahead for a few seconds or more, and if an obstacle is detected ahead, a chime and flashing light sequence begins. As the car gets closer, the system will gently apply the brakes on its own. As the car gets closer to the obstacle, the system reprograms the steering ratio for quicker response, and cinches up the seat belts, and prepares the brake system to respond with full force when activated by the driver before impact.
We reluctantly tested the Intuitive Park Assist system, thinking anyone who knows how to parallel park will consider this an unnecessary, slightly insulting adornment. However, it really works. Actually, it works great. We found ourselves using it over and over. The trick is to scan in the exact size of the parking space, then keep a foot on the brake while the car automatically maneuvers itself into the spot. It takes about 10 seconds.
