4th Gen. Lexus Flagship Luxury Sedan Features Host of World and Segment Firsts in Preventive Safety

"The Lexus LS 460 was designed to expand on the definition of the full-size luxury sedan as well as the level of innovative technology, especially as it relates to safety," said Bob Carter, Lexus group vice president and general manager.

Lexus showcased numerous ground-breaking developments in the area of accident-avoidance and collision damage mitigation systems available on the new LS sedan. Among the most significant announcements was a revolutionary, state-of-the-art advanced Pre-Collision System designed to help protect not only its occupants but also pedestrians. This innovative system includes several world firsts: an Advanced Obstacle Detection System, an Emergency Steering Assist, a Lane-Keeping Assist System and a Driver Monitoring System.

Ultra Advanced Dynamics

The new LS is built on a sophisticated platform that maintains a delicate balance between ride comfort and responsive handling. The LS 460’s active safety equipment—a completely redesigned multilink suspension system—is highlighted by two segment firsts: Variable Gear Ratio Steering (VGRS) equipped on the available air suspension and a next-generation Vehicle Dynamics Integrated Management (VDIM) system, coupled with electronic power steering. These key Lexus technologies establish a link between active and preventive safety.

Variable Gear Ratio Steering employs an actuator attached to the intermediate steering column shaft, which alters the steering gear ratio according to vehicle speed. At very low speeds, the gear ratio is at its lowest in order to reduce both the steering input and effort required during tight cornering and parking maneuvers; at medium speeds, the gear ratio is
optimized for light, accurate vehicle response when cornering; and at high speed the ratio is at its highest to help ensure gentle response to inputs and maximum vehicle control. In addition, VGRS connects with other safety systems in order to help ensure the most rapid steering response possible when necessary.

VDIM is a technologically advanced system that helps the driver stay in control by processing comprehensive status data provided by sensors throughout the vehicle. It integrates the new LS 460’s Electronically Controlled Brake (ECB) system, Electronic Power Steering (EPS), Vehicle Stability Control (VSC), Traction Control (TRAC), Antilock Braking System (ABS), Brake Assist (BA), Electronic Brake-force Distribution (EBD) and engine torque via the electronically controlled throttle.
Monitoring a variety of sensors, the system is designed to anticipate the onset of a vehicle skid or slide and then help correct the situation with a combination of braking, throttle and steering control in a way that is essentially transparent to the driver. Data is gathered from more sources and processed earlier and faster than in previous designs, helping to make VDIM less obtrusive and even more effective. In addition, this stability-control system helps to enhance performance and traction control.

The new LS 460’s Electronically Controlled Brakes (ECB) make it the only car in the segment to feature a by-wire braking system. This innovative system results in a reduction in overall brake-system weight while allowing a more precise brake-force distribution, which helps to enable optimal operation of VDIM and other brake-control systems. The brake system generates unparalleled stopping power through the adoption of four-piston brake callipers to the front and two-piston callipers to the rear, both fabricated in aluminum to reduce unsprung weight.

LS Makes Strides in Preventive Safety

The new Lexus flagship takes anticipatory, preventive safety to new heights by debuting several world and segment firsts in this area. This unprecedented combination of preventive safety features is designed to recognize potentially dangerous situations in advance and helps to reduce the chances of an actual collision, which in turn helps to provide enhanced protection to not only vehicle occupants but also, for the first time, to pedestrians.

In a significant development of the already advanced Pre-Collision System available on all Lexus sedans, engineers at the Lexus Development Center in Aichi, Japan have incorporated new features that anticipate and automatically react to several types of frontal collisions, even after dark.

Thanks to millimeter-wave radar and stereo cameras, the Advanced Obstacle Detection System can detect a wide range of obstacles in the path of the LS 460 including, for the first time, pedestrians and animals. When there is a high probability of a frontal collision, an alarm will prompt evasive action by the driver. However, if the system concludes that a collision is unavoidable, the Pre-Collision seatbelts’ retracting mechanism will be activated and the brakes will be automatically applied to help reduce the consequences of the impact.

Moreover, Emergency Steering Assist aids in substantially improving the vehicle’s response to the driver’s steering input in the likelihood of a collision, increasing the chances of avoiding the obstacle. This is achieved through a close interaction between VDIM and available VGRS with Adaptive Variable Suspension (AVS), providing a more direct steering gear ratio, selective brake control when necessary and a stiffer suspension setting.

A further element of the enhanced Pre-Collision System, the first ever Driver Monitoring System constantly tracks the movement of the driver’s face through a miniature camera installed on the steering column. If an obstacle is detected in front of the vehicle when the driver is not looking forward, the system sounds an alarm as well as initiates momentary, gentle braking to alert the driver.

Additional Protection in Lexus’ Passive Safety Systems

In order to assist in protecting occupants from the consequences of a collision, a robust safety structure capable of absorbing a high degree of impact energy and several strategically placed SRS airbags offer another line of defense.
In addition to front, side and side-curtain airbags, the new LS also features SRS knee airbags for both front passengers. This device helps distribute the loads imposed on the body by the severe impact deceleration which occurs in a crash.
Furthermore, the SRS Twin-chamber Passenger Airbag is offered in this segment for the first time. It features an advanced shape based on the Lexus Omni-Support concept. Once inflated, the twin chambers create a depression in the center of the airbag, helping to disperse the physical impact of the bag across numerous other head and shoulder body contact points.

LS Sedans Add Advanced Lane-Keeping Assist

The Lexus LS 460 will feature a Lane-Keeping Assist system, an innovative driving assistance function that will help the driver to determine if the vehicle is deviating from its lane. Based on white road-line information captured by the stereo cameras, an alarm is activated and steering rotation is automatically applied for a short period of time to help guide the vehicle back into its lane. In addition, when the Adaptive Cruise Control is active, “steering power support” is provided to help to ensure that the vehicle is centered in its lane—again based on the white road-line information. The driver can, however, always override this automatic steering action at any time.

The full advanced Pre-Collision System package, comprised of the Advanced Obstacle Detection, Emergency Steering Assist, Lane-Keeping Assist and Driver Monitoring systems, will be optionally available on all LS sedans beginning in April 2007.

Powerful Partners: High-Output V8 and World’s First Eight-Speed Automatic Transmission
The LS will be powered by an all-new, highly advanced 4.6-liter V8 engine that will produce approximately 380 horsepower and 370 pound-feet of torque. Combined with a world-first eight-speed automatic transmission, the LS 460 will travel from zero-to-sixty miles per hour in less than 5.5 seconds—all without sacrificing fuel economy. Even with this level of performance, the new LS is expected to receive a combined city/highway mileage in the low-20s. Lexus is targeting an Ultra-Low Emissions Vehicle II (ULEV II) rating for the LS 460.

The 2007 Lexus LS 460 and LS 460L are targeted for sale beginning in the fall of 2006. Pricing will be announced as the on-sale date approaches.

Preliminary Specifications