Lexus technology: state of the art, 2005 and onwards
Safety (added 2006)
Toyota has developed a system that, using radar, anticipates rear-end collisions and move the headrests to avoid whiplash. The computer-controlled system is used in the 2007 Lexus LS sold in Japan.
All Lexus engines (except the LX 470) use continuously variable valve timing with intelligence (VVT-i) to boost low-end, midrange, and high-end power, giving them the feel of larger engines without the gas mileage hit. VVT-i eliminates the traditional compromise between low-end torque and high-rpm horsepower by optimizing valve overlap throughout the engine’s speed range, not just at one or two set speeds. Most Lexus models are certified as Ultra Low Emissions Vehicles (ULEV), and the Lexus passenger car 4.3-liter V8 was one of the first V8 engines to achieve this certification.
The 4.3 V8 has Intuitive Powertrain Control; working with the electronic throttle control, this system helps to smooth out acceleration from a standing start by very slightly delaying throttle opening when the driver steps on the accelerator.
Performance is not just acceleration, and the GX 470 has an optional Kinetic Dynamic Suspension System (KDSS), which uses electronically controlled hydraulic cylinders to vary the degree of sway resistance provided by the front and rear stabilizer bars.
Comfort and Convenience
Five Lexus models offered a rear backup camera in 2005, including the LS 430 sedan and all three SUVs. The camera comes as part of the navigation system (standard in LX 470) and projects a color image on the navigation system’s screen when in reverse.
The flagship LS 430 sedan and the RX 330 luxury utility vehicle offer two modes of cruise control: the conventional cruise control and a Dynamic Laser Cruise Control. The laser cruise control system, which collects data from 630 scanning points, is designed to help the driver automatically maintain a set distance from the vehicle traveling in front. (LS 430 models equipped with the Pre-Collision System feature a radar-based dynamic cruise control system. In place of laser beams, as used in the Dynamic Laser Cruise Control system, a millimeter-wave radar system is designed to detect vehicles traveling ahead.)
The ES 330 and RX 330 use an active engine mount that helps keep even the smallest vibrations from reaching the passenger compartment. A solenoid-controlled diaphragm produces pulses equal-but-opposite to those of the engine, helps to absorb vibration with every power stroke.
The optional Ultra Luxury Selection for the LS 430 includes air suspension that integrates a semi-active damping system called Adaptive Variable Suspension (AVS). Responding to road conditions, driver input and vehicle speed, AVS continuously adjusts the shock absorber damping force to help provide the best balance of ride comfort and handling response. The AVS system is also standard on the LX 470 and GX 470, and is available as an option on the entry luxury ES 330 sedan — a rarity in its segment.
All Lexus models come equipped with automatic climate control. The system in the LS 430 features temperature and sun-sensing intelligent swinging registers. If sunlight is concentrated on one side of the car, the registers will automatically deliver more cooling air to that side. Also, the system uses seatbelt buckle sensors to detect if there are passengers and directs air accordingly.
In the SC 430 hardtop convertible, an advanced climate control system makes top-down driving more comfortable by adjusting airflow and temperature automatically, differentiating between top-up and top-down driving needs.
The LS 430 offers a rear air conditioning system with an optical deodorizer. The unit uses a catalyst-coated filter and an ultraviolet light to help break down odor-causing elements.
DVD Navigation System
Lexus offers a DVD-based global satellite positioning (GPS) navigation system in all models for 2005 (standard in LX 470 and SC 430). It was the first brand to offer this technology across its model line. A single DVD disc holds all the map data for the contiguous United States and additional areas in Canada.
All systems use a high-speed navigation computer that offers multi-language selection, high-speed route calculation (average of five seconds) and fast map scrolling. Convenient features include multi-route calculation, route preview, simplified highway junction graphics and a dual-map screen mode.
The navigation system in most Lexus models for 2005 incorporates improved screen graphics, phone number-based address location, and building footprint display for several major cities. The database contains more than five million points of interest, compared to two million for the previous system. The map database for Chicago, Detroit, Los Angeles and New York features “building footprint” graphics, which shows renderings of the building in its location. This feature can be useful for identifying buildings and their surroundings — helpful for example, when looking for nearby landmarks. Additional functions of the navigation system vary by vehicle.
The LS 430 uses a large seven-inch screen and incorporates voice command recognition, the latter feature also included with the ES 330’s navigation system and added to GX 470 model for 2005. The driver can operate the system totally hands-free using 300 different voice commands. The navigation systems offered in the ES 330, SC 430, GS sedans and RX 330 feature touch-screen technology.
In the LX 470, the display screen provides an in-car theater. When the transmission selector is in the “Park” position and the parking brake is set, passengers can view a DVD movie. When the selector is in the “Drive” position, passengers can listen to the sound but can’t view the video.
The SmartAccess feature available for the LS 430 allows the driver to unlock the car simply by touching the door handle (with remote control in pocket or purse) and then start it at the touch of a button. The SmartAccess key fob, carried in the driver’s pocket, transmits a radio signal to onboard antennas, authorizing the security system to unlock the car and permit engine starting. The system includes a SmartAccess key wallet card that allows the driver to unlock and start the car if the main key fob is lost. A similar system is used on the Toyota Prius.
Lexus is the only automaker to offer an OEM mobile audio system designed by Mark Levinson®. The system is standard equipment in the SC 430 hardtop convertible and available as an option in all other Lexus models except the IS 300. The Lexus systems feature discrete amplifier design with ultra-low crossover distortion. All occupants enjoy optimal sound quality no matter where they’re sitting in the vehicle.
All Road/Off-Road Travel
The GX 470 features two systems to help control the vehicle in rugged driving conditions. Downhill Assist Control (DAC) augments the low-speed descending ability of low-range by holding the vehicle to a comfortably low target speed with no intervention from the driver. In addition, the Hill-start Assist Control (HAC) system helps provide additional control for off-road driving by softly braking the vehicle if it rolls backward on a steep slope.
The LX470's standard hydraulic Adjustable Height Control (AHC) allows the driver to raise the LX 470 and the GX 470 to negotiate particularly rough off-road terrain, and to lower it for easy entry and exit. A height control switch and light indicate current suspension height and flashes when height changes occur. If set in high mode, the suspension will automatically lower when the LX 470 exceeds 18.6 mph. For off-road travel, switching to “high” increases the angle of approach from 30 to 32 degrees and the angle of departure from 23 to 26 degrees to help the vehicle “step over” obstacles. The vehicle will go into “extra high” mode if it is in low range and traveling in rough terrain, with the height rising automatically by 1.2 inches at the front and approximately 1.8 inches in the rear.
New for 2005, the RX 330 model incorporates roll-sensing curtain airbags, which are designed to deploy in a severe tilt angle, roll or lateral g force. (The GX 470 added this feature for 2004.)
In 2004, the LS 430 became the first Lexus model to offer the new Pre-Collision System (PCS), which is designed to help reduce collision severity and damage. This advanced new system uses a millimeter-wave radar sensor to detect obstacles in front of the car and a pre-collision system computer with vehicle speed, steering angle and yaw rate inputs that helps to determine in advance whether a collision is unavoidable. If PCS determines that a collision is not avoidable, it can preemptively activate the Pre-Collision seatbelt to retract the driver and front passenger seatbelts prior to the collision. To help reduce collision speed, the Pre-Collision Brake Assist automatically applies maximum braking force as soon as the driver applies the brakes.
The Supplemental Restraint Systems in all Lexus models include dual front airbags and front seat-mounted side airbags. Mounting the side airbags in the seats helps keep them consistently positioned relative to the occupant regardless of a front seat’s position. The RX 330 and ES 330 models feature side airbags that help manage impact energy for a larger area, including the torso, abdomen and pelvis.
All Lexus models include seatbelt pretensioners and force limiters for the driver and front passenger. The ES 330 model adds these features to the rear seats for 2005.
Most Lexus models come standard with side curtain airbags (SRS) for the driver and front passenger, in addition to side airbags mounted in the front seats. In the LS 430 and ES 330, the side curtain airbags extend from the A-pillar to C-pillar to help manage impact energy for the head and upper body in certain types of severe side impacts.
All Lexus SUVs have front and middle-row side curtain airbags (roll-sensing in LX 470, GX 470 and RX 330). The IS 300 and GS models include side curtain airbags for the driver and front passenger.
Advanced front airbags in most Lexus models deploy at different speeds, depending in part on the severity of an impact. The driver’s front airbag includes an extra low or low deployment stage when the seat is positioned on its track close to the steering wheel. The LS 430 features driver and front passenger knee airbags, and the RX 330 is equipped with a driver’s knee airbag. The ES 330 and LS 430 also come equipped with whiplash injury-lessening (WIL) front seats.
A Tire Pressure Monitor (TPM) is standard on the LS 430 and the SC 430, as well as the GX 470 and RX 330. If a significant drop in pressure has occurred, a warning light illuminates. When pressure drops even further, the light flashes and a buzzer sounds.
Lexus equips most models with a water-repellent coating on the front door window glass.
All Lexus models come with standard fog lights, and all can automatically turn the headlights on at dusk and also while driving through dimly lit areas, such as tunnels. An electrochromic auto-dimming interior rearview mirror is offered on all Lexus models, and most offer auto-dimming outside mirrors as standard or optional equipment. These mirrors can enhance night driving by greatly reducing glare from headlights of vehicles following behind.
The Adaptive Front lighting System (AFS), which helps illuminate a turn or curve as the driver steers into it, is standard on the LS 430 and available as an option on the RX 330. A central controller calculates the optimum lighting direction based on input from vehicle speed and steering angle and swivels the right and left headlights independently. The left beam can rotate from 0 to 15 degrees in a left turn while the right beam remains in the center position. The right beam can rotate from 0 to 5 degrees in a right turn while the left beam remains in a center position. As a result, this helps the driver see further into a curve.
The AFS headlamps also have a self-leveling feature (similar to HID headlights) that levels the lights depending on road conditions. An AFS on/off switch allows the driver to disengage the AFS system at any time.
The LX 470 offers an option called Night View, which uses near-infrared technology that is designed to help give the driver illuminated images of what is ahead of the vehicle out to a distance of nearly 500 feet. Night View projects near-infrared beams from two lamps in the lower grille. The near-infrared light reflects from objects ahead back to a camera mounted inside at the top of the windshield. A dedicated computer processes the resulting natural-looking images, which are then projected onto a section of the windshield in the driver’s field of vision.
All Lexus models come equipped with four-channel, four sensor anti-lock brakes (ABS) to help maintain steering control during emergency braking maneuvers. In the GX 470 and LX 470 luxury utility vehicles, the ABS operates even in low-range four-wheel drive. Sensors monitor road conditions according to changes in wheel speed. Such responsiveness helps the driver maintain control while traversing hilly, unpaved terrain.
Most Lexus models are equipped with Electronic Brake-force Distribution (EBD), which helps to optimize brake pressure at each wheel, especially during braking while cornering. All Lexus vehicles offer the Brake Assist system which is designed to determine if the driver is attempting emergency braking and, if the driver has not stepped firmly enough on the brake pedal to engage the ABS, Brake Assist applies maximum braking pressure until brake pressure is released.
Most Lexus models include as standard equipment Vehicle Stability Control (VSC), which also incorporates traction control (TRAC). The LX 470 and the GX 470 come with VSC and Off-Road TRAC. VSC detects front wheel slide and rear wheel slide and attempts to control either by using the throttle and/or by braking individual wheels. The system also performs as traction control on the drive wheels, helping control wheelspin on slippery road surfaces. TRAC uses either the throttle or brakes to restore traction.
TRAC, VSC, and Brake Assist employ the sensors and actuators of the standard four-channel anti-lock brake system. VSC also relies on a yaw rate sensor and a dedicated computer.