- Standard Vehicle Dynamics Integrated Management Handling Technology
- Lexus Hybrid Drive Systems Operates in Electric-Only, Gas-Engine-Only or Combined Modes
- Achieves Super Ultra Low Emission Vehicle Certification
As a full hybrid, the RX 450h can operate in electric-only or gas-engine-only modes as well as a mode that combines the power of both. Extended electric-mode operation during low-speed or stop-and-go driving conditions helps reduce fuel consumption. Under certain circumstances, a driver-selectable EV mode can allow the vehicle to be driven short distances using only the electric motors. The RX 450h achieves Super Ultra Low Emission Vehicle (SULEV) certification in California (Tier 2-Bin 3 in other states).
With the Atkinson cycle, the gasoline engine’s intake valves are closed late to delay beginning of compression, resulting in a higher expansion ratio. That reduces intake and exhaust energy losses for more efficient combustion and improved fuel economy. The gas engine alone produces 245 horsepower at 6,000 rpm and 234 lb.-ft. torque at 4,800 rpm. The Atkinson cycle also reduces exhaust temperature.
The RX 450h FWD model’s hybrid powertrain employs two motor-generators: MG1, the engine-driven generator, is a starter and can charge the battery pack or power other electric motors as needed; MG2 is the front-drive motor. Power from the gas engine and MG2 is distributed to the drive wheels via a planetary gear-type continuously variable transmission. MG1 controls the output speed of the transaxle through the planetary gear set, without clutches or a viscous coupling. MG2 delivers torque over a wide range for better response and smooth performance. When the RX 450h is coasting or braking, the electric motors function as generators, capturing energy that would normally be lost as heat through the brakes and transforming it into electricity to recharge the batteries.
RX 450h AWD adds a third, rear-mounted motor-generator (MGR) to drive the rear wheels, eliminating the need for power-transfer gearing or a driveshaft from the front. The hybrid system electronically varies front and rear torque distribution depending on traction conditions. A two-step flywheel damper absorbs small torque fluctuations and also the minor vibration produced when the gasoline engine starts and stops. A SNOW mode slows accelerator-pedal response to help reduce the possibility of wheel spin.
Multi-Mode, a feature adapted to the vehicle’s electronically controlled continuously variable transmission, allows the driver to control engine braking for enhanced maneuverability on rough or winding roads. The Intelligent Shift Control feature selects and holds the optimal range when driving downhill or on inclines, providing a smoother driving experience.
The power-steering pump, water pump and air-conditioning compressor are driven electrically rather than by the engine, reducing parasitic losses.
To enhance fuel economy, an exhaust heat-recovery system circulates engine coolant through a unit installed in the exhaust pipe behind the catalytic converter. This feature reduces engine warm-up time, allowing it to stop earlier, more often, and for longer periods, improving both fuel economy and emissions.
The standard electric power steering system contributes to agility and better steering feel while eliminating the parasitic losses of a hydraulic steering pump. Eliminating hydraulic oil also provides an environmental benefit and reduces maintenance. When the driving conditions involve little steering input, energy consumption is reduced, improving fuel economy by nearly three percent. Steering assist is automatically adjusted in response to vehicle speed, with greater assist at low speeds and greater feel at higher speeds. In addition, maneuverability in the RX is easy with its 40 foot turning circle curb-to-curb.
Vehicle Dynamics Integrated Management (VDIM) handling technology is standard on the RX 450h. VDIM system anticipates loss of vehicle control and governs all of the vehicle’s dynamic handling systems – the Anti-lock Braking System (ABS), Brake Assist (BA), Vehicle Stability Control (VSC) and Traction Control (TRAC) – with the electronic throttle control system. The system employs them collectively and seamlessly to help make corrections while allowing higher dynamic capability.
The system’s enhanced VSC function adds steering assist torque to help aid handling on a split-friction surface. The VDIM system also provides a limited slip differential effect. The TRAC and VSC functions can also be switched off, for example, when the driver needs to free the vehicle when stuck in mud or snow.
Standard 18-inch aluminum-alloy wheels, which were designed to appear as if carved from a single block, have 235/60R18 tires. Optional 19-inch split five-spoke aluminum-alloy wheels with 235/55R19 tires are available with a hybrid-exclusive design.
Also available is an automatic high beam system which uses a camera mounted on the inner rear view mirror to switch between high and low beams in response to oncoming vehicles and those traveling in front, or when other ambient sources are detected, helping reduce driver inconvenience.
The optional Pre-Collision System (PCS) with Dynamic Radar Cruise Control uses millimeter-wave radar to measure and help maintain a pre-set following distance from a vehicle traveling ahead. The radar sensor can detect certain obstacles in front of the car, and a PCS computer with vehicle speed, steering angle and yaw-rate inputs helps to determine whether a collision is highly possible. In such a situation, PCS preemptively retracts front seat belts and pre-initializes BA so that increased braking will be applied the instant the driver depresses the pedal.
A high-strength cabin design and comprehensive Supplemental Restraint Systems (SRS) are designed to help provide a high level of crash-energy management. Approximately 42 percent of the entire structure uses high tensile strength steel. The structure was engineered to help provide collision compatibility with vehicles of varying heights and weights.
The RX 450h is equipped with a segment-leading 10 standard airbags, including side curtain airbags, front seat-mounted side airbags, rear side airbags (for the outboard seating positions) and knee airbags for the driver and the front passenger. A roll sensor signals the side curtain airbags to inflate if a predetermined threshold of vehicle tip-up is detected.
RX 450h is equipped with a power tilt and telescopic steering column. To ease entry and exit, the seat automatically slides up to two inches rearward and the steering wheel tilts upward and slides forward when the hybrid system is switched off. Upon pushing the “ON” switch, the seat and steering wheel return to their last position automatically.
The standard 10-way power front seats are shaped to accommodate arm movement when operating the available Remote Touch, while helping to hold the occupants in place. Both the driver and passenger seats also feature power lumbar adjustment. Also available on the RX is a ventilation function for the front seats to help improve comfort on hot and humid days. The shape and texture of the armrests and switches offer an ideal combination of tactile feel and functionality.
The leather-wrapped three-spoke steering wheel features integrated audio controls and a unique cross-section that is designed to provide a more natural grip than a conventional round-section wheel. An optional leather and wood trimmed wheel is also available.
Three seat materials include standard fabric, optional smooth leather or even softer semi-aniline leather. The RX 450h also exclusively offers a Black and Light gray interior with striking black accents. In addition to Light gray and Black, Parchment is available as an interior color. Standard wood trim comes in Brown Walnut matched to Parchment, or Espresso Bird’s-eye Maple matched to Light gray and Black.
The RX continues the tradition of offering the Lexus Premium Audio system as standard equipment, in this case a powerful nine-speaker system with a six-disc changer. Creative placement and angling of the speakers perfectly cross-channel sound to the occupant on the opposite side of the vehicle to transform the cabin into a clear, crisp acoustic environment. Bluetooth® hands free phone capability is also standard.
RX models can accommodate a variety of music sources, providing available auxiliary and USB inputs, Bluetooth Audio wireless connectivity and a standard integrated XM Satellite Radio receiver (complimentary 90-day trial subscription included). When an iPod® is attached via the USB port, information such as names for the artist, track and album is displayed on the available navigation or audio screen, while the iPod can be controlled through the audio system. The large center console storage box easily accommodates a variety of electronic devices while keeping wires out of sight.
The optional 15-speaker Mark Levinson® Surround Sound system allows listeners to enjoy 330 watts at 0.01 percent THD through 7.1-channel surround sound. The Mark Levinson system, a Lexus exclusive, features a center channel coaxial speaker, metal-cone midrange speakers, tweeters and a 100-watt amplified subwoofer. A 2.5-inch speaker built into each D-pillar provides the right and left surround-sound channels. The diffusion of sound provides each occupant the same level of audio quality.
The available Hard Disc Drive (HDD) navigation system eliminates the need for DVD map discs and offers a unique voice recognition system, which can work using casual-language inputs on certain functions. An optional rear-seat entertainment system includes two high-definition seven-inch screens, one on each of the front seatbacks. Each screen can display video from separate sources. A remote control allows independent control of each screen. Rear-seat occupants can also choose to listen to audio through the wireless headphones instead of vehicle speakers.
RX 450h also offers a telematics system, Lexus Enform® with Safety Connect®, available by subscription. Complimentary one-year trial subscriptions are included on all purchases of new Lexus vehicles equipped with these features. Safety Connect is standard on all vehicles while Lexus Enform with Safety Connect is on all vehicles equipped with the optional Navigation system. The Lexus Enform and the Safety Connect response centers operate 24 hours a day, 7 days a week—every day of the year.
Lexus Enform vehicles are factory ready for subscriptions to a variety of innovative SiriusXM services including NavTraffic, NavWeather, Sports, and Stocks. SiriusXM services include complimentary 90-day trial subscriptions and require separate audio and data subscriptions.
The Lexus design cue of placing the grille lower than the headlights, along with sharper headlight graphics, yields a strong frontal expression. The RX 450h offers standard halogen and optional HID and LED headlights. The RX 450h’s unique grille features a finer pitch than on the RX 350, creating a fluid-like surface, accentuated by its silver color.
Pronounced front fenders flow into the doors, and integrated rear fender flares neatly sweep around to pull together the taut rear corners of the vehicle. The lower body emphasizes the standard 18-inch wheels. Passenger doors extend below the entry sill, helping keep out dirt and moisture.
Several exclusive design features, including the grille and front bumper, distinguish the RX 450h hybrid from the RX 350. Exclusive optional LED headlights offer a more distinctive appearance as well as longer life and lower energy consumption. Lexus hybrid blue is used for the front and rear emblems, hybrid logos, rear combination lights, and headlights.
A distinctive feature of the door handles is that the surface subtly twists outward from the front to the rear to give a comfortable grip. The side mirrors feature integrated LED turn signal lamps.
The rear spoiler’s primary function is to help lower the vehicle’s Coefficient of drag (Cd), but it also conceals the rear wiper and houses the AM/FM radio antenna and high-mount stop lamp.
A high contrast white Organic Light Emitting Diode (OLED) is used for the multi-information display located next to the speedometer. Vibrant white characters are sharply displayed on a high-contrast black background for ease of use and a luxurious appearance. For the RX 450h, blue accented meters strengthen the hybrid image, and a hybrid system indicator replaces the tachometer to encourage driving in an economical manner.
In addition to an Eco Driving indicator light, RX models feature an Eco driving indicator zone that displays current fuel economy using a bar graph and alerts the driver when they are achieving low fuel efficiency.
The available navigation system can be controlled using either the Remote Touch device or by utilizing voice command. Remote Touch allows the user to operate the navigation system, climate, audio, phone controls and more. The screen menus are selected with the controller, eliminating the need to reach out and reducing eye movement.
The available Heads-Up Display (HUD) utilizes white readouts. High-intensity LEDs project high-contrast white figures onto the windshield, which are easier to read – and easier on the eyes – than the typical green-colored readouts. The HUD offers displays for speed, navigation, and audio. A wedge-shaped windshield interlayer for the HUD projection area eliminates the distracting printed grid pattern seen on some other vehicles equipped with HUDs.