2010 Lexus RX450h Hybrid Review & Test Drive


Since its original introduction in 1998, the world’s first luxury sport utility vehicle has sold more than one-million units around the world.  In 2005 Lexus introduced the first RX Hybrid and the rest is history.  For the 2010 model year, Lexus raises the bar on style, versatility, luxury and efficiency with the introduction of the all-new Second-Generation 2010 RX450h.

The RX450h’s Lexus Hybrid Drive features a 3.5 liter V6 Atkinson-cycle engine, electric motors, a small and light power-control unit and other fuel-saving innovations.  It offers up performance similar to V8 engines with a total of 295hp and better combined fuel economy than many four-cylinder mid-size sedans.  The front-wheel-drive (FWD) model that I tested has an EPA-estimated 32mpg/city and 28mpg/highway fuel economy ratings, while the all-wheel-drive (AWD) model has an estimated 30mpg/city and 28mpg/highway rating.

As a full hybrid, the RX450h 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 rX450h 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 245hp at 6,000rpm and 234lb.ft. of torque at 4,800rpm.  The Atkinson cycle also reduces exhaust temperature.  A cooled Exhaust Gas Recirculation (EGR) system reduces it further still, helping economy by eliminating the fuel enrichment otherwise needed to help prevent catalyst overheating under high loads.

A compact 288V DC Nickel Metal Hydride (Ni-MH) battery pack fits neatly under the rear seat.  A boost converter efficiently raises voltage to 650V DC, and an inverter changes this to 650V AC for the front-mounted 123-KW electric motor generator.  The boost converter and inverter are enclosed in the power-control unit, which also house the condenser.

The RX450h 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 the 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 that is very quiet and seamless.  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 RX450h 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.

The RX450h AWD model adds a third, rear-mounted motor-generator 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 acceleration-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 you to control engine braking for enhanced maneuverability on rough or winding roads.  The AI-SHIFT 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 AC compressor are driven electrically rather than by engine, reducing parasitic losses for more efficiency. To further enhance fuel economy, an exhaust heat-recovery system circulates engine coolant through a unit installed in the exhaust pipe behind the catalytic converter.  This advanced feature reduces engine warm-up time, allowing it to stop earlier, more often, and for longer periods, improving both fuel economy and emissions.

I truly enjoy driving the new RX450h with its engaging driving experience plus its smooth and quiet ride.  A key factor in the RX450h is its handling agility thanks to its   fully independent suspension with a MacPherson strut setup in front and its uniquely designed double-wishbone setup in the rear.  Another key benefit of the rear suspension is that the packaging yields great cargo area room.  The front suspension geometry was optimized with a thick stabilizer enhancing cornering ability and inversely wound coil springs compress in opposite directions, preventing the negative effects of suspension compression on steering.

The standard electric power steering system contributes to agility, precision and better steering feel while eliminating the parasitic losses of a hydraulic steering pump.  Eliminating hydraulic oil also provides an environmental benefit and reduces maintainance.  When the driving conditions involve little steering input, energy consumption is reduced, improving fuel economy by nearly 3%.  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 RX450h is easy with its 40ft. turning circle.

Helping to keep you on your chosen path is the standard Vehicle Dynamics Integrated Management (VDIM) handling technology system.  VDIM system anticipates loss of vehicle control in virtually any direction and governs all of the vehicle’s dynamic handling systems-ABS, 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 you need to fee the vehicle when stuck in mud or snow.

The RX450h stops with the help of two-piston calipers clamping on 12.9in. vented front disc brakes with single-piston calipers grabbing 12.2in. solid discs.  These power-assisted brakes feature optimized brake pads to add friction, pedal ratio, and booster output characteristics, all enhancing braking power and control.  The RX450h’s electronically controlled brakes (ECB2) work closely with VDIM, translating brake pedal stroke speed and pressure to generate the precise amount of hydraulic pressure needed.

Standard Hill-start Assist Control uses brake pressure to help prevent the vehicle from moving backward when starting out on an incline.  This system does not wait to detect rollback, however.  It can be controlled by the driver and works in both forward and reverse.  While the vehicle is stopped and brake the pedal is depressed, pushing it further activates the feature.  Brake pressure is then maintained for approximately two seconds after the brake pedal is released and you switch over to the accelerator pedal.

The RX450h rides on standard 18X8in. aluminum-alloy wheels which were designed to appear as if carved from a single block, have 235/60R18in. tires.  My RX450h came with the optional 19X8in. alloy wheels wrapped with 235/55R19in. all-season tires.

The ergonomics and luxury inside is what really sets the RX450h apart from other hybrid crossover vehicles.  All RX models come equipped with the SmartAccess keyless entry with push-button start/stop.  As you approach the vehicle, interior and exterior courtesy lamps illuminate.  Opening the door, the instrument panel lighting gradually fades in.  When the hybrid system is started, the instrument cluster gauge needles and markings illuminate, followed by the multi-information display.  After you exit the vehicle, the lights fade out at different intervals.

The RX450h is also equipped with a power tilt/telescopic steering wheel that feels perfect in your hands.  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’ button, the seat and steering wheel return to positions pre-set by the driver using the three-position memory system.

The standard 10-way power front seats are shaped to accommodate arm movement when operating the available Remote Touch, while also holding you firmly yet comfortably in place during spirited driving times.  Both driver and front 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.  Lexus stylists and designers also added their excellent and signature attention to workmanship and detail.

The leather-wrapped three-spoke steering wheel features integrated audio control 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 available and it felt supreme when holding or turning the wheel, enhancing my grip and control.

Three seat materials include standard fabric, optional smooth leather or even softer semi-aniline leather.  In addition to light gray and black, Parchment is available as an interior color.  The RX450hp also exclusively offers a black and light gray interior with striking black accents that I had inside my text model.  Standard wood trim comes in brown Walnut matched to Parchment, or Expresso Bird’s-eye Maple matched to gray and black.

The center console holds dual cupholders below a flip-open top and the console box provides a padded armrest and 0.75cu.ft. of storage capacity.  The three-part (40/20/40) rear seats can slide fore and aft, recline and fold down using the one-touch levers mounted in the luggage compartment.  There is also a pull-down armrest with dual cupholders and storage.  The rear of the center console also has dual air-intake to more effectively channel warm or cool air into the rear seats.

The quiet dual-zone climate-control system offers quick cooling and warming.  A high-efficiency compressor detect refrigerant flow in order to optimize engine control and fuel economy.  An available smog sensor is designed to detect harmful particles in other vehicle’s exhaust emissions and automatically switch between fresh air and recirculation modes.  An electric compressor on the RX450 includes a humidity sensor to help optimize air-conditioner operation, helping to enhance fuel economy further.

The standard Lexus Premium Audio System is a powerful 9-speaker system with six-disc changer.  Creative placement and angling of the speakers perfectly cross-channels 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. The audio system provides available auxiliary and USB and iPod inputs.

Standard equipment not mentioned above includes all express up/down windows, door locks, power remote side mirrors, self-dimming rearview mirror, rain-sensing wipers/washers, rear wiper/washer, dual map lamps, cruise-control, grab handles above each door, one-touch electric sunroof, large lighted glove box, storage slots in each door, and thick cut-pile carpeting.

Luxury options start with a 12-speaker audio system that comes with the optional navigation or rear-seat entertainment systems that includes two-rear-door tweeters and a compact L-shaped subwoofer in the rear luggage compartment.  The optional 15-speaker Mark Levinson Surround Sound system allows listeners to enjoy 7.1-channel surround sound.  The optional Hard Disc Drive 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.  Available wide-view side and backup cameras help provide you with a wider range of visibility.  An optional roof rack expands your cargo carrying capacity.

The new RX450 also offers a telematics system, Lexus Enform with Safety Connect, available by subscription.  Complimentary one-year trial subscriptions are included in all purchases of new Lexus vehicles.  Safety Connect is standard on all new Lexus vehicles while Lexus Enform with Safety Connect is on all equipped with the optional navigation system.  The Lexus Enform and Safety Connect response centers are open 24 hours a day, 7-days a week-every day of the year.

Based on the L-finesse philosophy, the dramatically designed interior clearly separates the interior into two distinct zones-the ‘display zone’ to provide information, and the ‘operation zone’ for interaction with all of the controls.  The shoulder of the door trim comfortably envelops the front occupants, the clear line of the trim beginning inside the cabin and tapering outward toward the exterior.  The design imbues a feeling of a continuous line encircling the front occupants and defining the controls and displays.  Neatly sculpted metallic surfaces, especially on the asymmetrical center stack, showcase a bold contrast of shadow and light.  A high-contrast white Organic Light Emitting Diode is used for the multi-information display located next to the speedometer.  Vibrant while characters are sharply displayed on a high-contrast black background for ease of use and a luxurious appearance.  For the RX450, 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 you when they are achieving low fuel efficiency.

I love driving the new RX450h; it is so comfortable, roomy, ergonomic and includes all of the modern touches and innovations only Lexus has to offer.  The center console mounted controller that operates all of the systems is like using a mouse with your computer.  Just click on menu, move the arrow to the system you want to use, click it and open a window on the 8in. screen and then move the mouse arrow to what you want the system to do.  It wonderfully simple to use and very quick reacting.

What really sets the all-new RX450h apart from the new crowd of hybrid crossovers is the exterior styling-sleek with a wide stance.  It is a dynamic blend of L-finesse design that creates a sleek profile that is accentuated by broad shoulders for an athletic yet elegant presence.  Bright finish side-window moldings follow a subtly concaved line across the A-and C-pillars extending at the front and rear ends.  The full-perimeter chrome trim at the bottom of the doors adds a touch of more luxury and carries the blue ‘hybrid’ logo.  The Lexus design cue of placing the grille lower than the headlamps, along with sharper headlamp graphics, yields a strong frontal expression.  The RX450h offers standard halogen and optional HID and LED headlamps.  the RX450h’s unique grille features a finer pitch than on the RX350, 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.  The lower boy emphasizes the standard 18in. or optional 19in. wheels.  Passenger doors extend below the aluminum sill plates, helping keep out dirt and moisture.  The rear spoiler’s primary function is to help lower the RX450h’s coefficient of drag but it also conceals the rear wiper and houses the AM-FM antenna and high-mount stop lamp.  In my opinion it is the most distinctive looking luxury crossover.

Lexus safety and security is among the best.  The RX450h features Adaptive Front-lighting System (AFS) for high beams of HID headlamp equipped models, and for the low beams of LED equipped models.  AFS can be switched off if desired and includes an auto-leveling function.  Also available is an automatic high beam system which uses a camera mounted on the inner rearview mirror to switch between high and low beams in response to oncoming traffic and those traveling in front.  The optional Pre-Collision System with Dynamic Radar Cruise Control (PCS) uses a 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 wheel 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 Brake Assist so that increased braking will be applied the instant you depress the brake pedal.  A high-strength cabin design and comprehensive supplemental restraint systems are designed to help provide a high level of crash-energy management.  Approximately 42% of the entire structure uses high tensile strength sheet steel.  The RX450h is equipped with a segment-leading 10-standard airbags, including side curtain airbags, front seat-mounted side airbags, and knee airbags upfront for both.  Active front headrests, roll-over sensor, pretensioners and load limiters up front help prevent serious frontal crash elements.

The all-new 2010 Lexus RX450h defines design, engineering and luxury innovations in the hybrid luxury crossover segment better than any of the competition.  The base price for a FWD RX450h is just $42,650.00 and $44,275.00 for the AWD model.



Price: Base RX450h $42,650 As-Tested $44,275
Type: Midsize SUV
Where Built: Canada/Japan
EPA Class: Sport Utility Vehicles


Length: 187.8 in.
Width: 74.2 in.
Height: 66.3 in.
Wheel Base: 107.9 in.
Ground Clearance: 6.9 in.
Curb Weight: 4652 lbs.

Front Head Room: 39 in.
Front Hip Room: 55.5 in.
Front Shoulder Room: 57.9 in.
Rear Head Room: 37.7 in.
Rear Shoulder Room: 57.5 in.
Rear Hip Room: 54.5 in.
Front Leg Room: 43.1 in.
Rear Leg Room: 37.1 in.
Luggage Capacity: 40 cu. ft.
Maximum Cargo Capacity: 80 cu. ft.
Maximum Seating: 5

Performance Data

Engine Number of Cylinders: 6
Engine Size: 3.5 liters
Engine Type: V6
Horsepower: 295 hp
Max Horsepower: 6000 rpm
Maximum Towing Capacity: 3500 lbs.
Drive Type: AWD
Turning Circle: 38.8 ft.
0-60mph: 7.2 seconds

Fuel Data

Fuel Tank Capacity: 19.2 gal.
EPA Mileage Estimates: (City/Highway/Combined)
Automatic: 30 mpg / 28 mpg / 29 mpg
Range in Miles:
Automatic: 576 mi. / 537.6 mi. / 556.8 mi.