Lexus RX 450h (2009 – 2015) Review

December 2008

World premiere of new RX

For the UK the RX 450h replaced both thre RX 350 and RX 400h making the RX range all hybrid. Lexus was the first and remains the only manufacturer to offer hybrid models in the segment in Europe, now presenting its second generation model before its rivals manage to bring their first hybrid contenders to the showroom.

4,770mm long x 1,885mm wide (+ mirrors) x 1,685mm high

Wheel and tyre sizes:

18-inch with 235/60 R18 tyres

19-inch with 235/55 R19 tyres.

Improvements over the RX400h include:

* Adoption of the Atkinson combustion cycle
* Cooled Exhaust Gas Recirculation (EGR)
* Exhaust Heat Recovery (EHR)
* New Power Control Unit
* Increased front and rear motor torque
* Reduced friction losses in hybrid transaxle
* Eco and EV driving modes
* AI-SHIFT control (Artificial Intelligence – SHIFT)

Total power output is 295bhp (299 DIN hp), enabling a top speed of 124mph and 0 to 62mph acceleration in 7.8 seconds. Conversely, the RX 450h has the lowest fuel consumption of any premium crossover model with a combined cycle figure of 44.8mpg. CO2 emissions are also remarkably low at just 148g/km.

The front drive unit is a series/parallel hybrid system featuring a 3.5-litre V6 chain cam VVT-I petrol engine, a powerful electric motor, a generator, a high performance battery, a power control unit and a power split device with a planetary gear set to combine and re-allocate power from the engine, electric motors and generator as driving conditions require.

The rear unit provides four-wheel drive by means of a second electric motor and is mechanically independent of the front unit. The motor is activated and continuously adjusted by the Vehicle Dynamics Integrated Management (VDIM) system, working in conjunction with the power control unit.

The 2GR-FE 3.5-litre (3,456cc) chain-cam DOHC petrol engine is based on that used in the RX 350, but has been adapted specifically for use in the hybrid powertrain. It produces a maximum 246bhp (249 DIN hp) at 6,000rpm and 317Nm of torque at 4,800rpm, and features three Lexus hybrid ‘firsts’ to optimise the fuel efficiency of the Lexus Hybrid Drive: Atkinson cycle combustion, cooled exhaust gas recirculation (EGR) and exhaust heat recovery (EHR).

In an Atkinson cycle engine the valves close late, delaying compression. This creates a high expansion ratio for less compression, reducing intake and exhaust energy losses and converting combustion energy into engine power more effectively. As a result the exhaust temperature is lower than in conventional engines.

EGR reintroduces cooled exhaust gas into the combustion chamber, further reducing the engine’s operating temperatures. Together these technologies minimise the need for any fuel enrichment to provide a cooling effect and protect the catalytic converter from overheating damage, thereby improving fuel economy and reducing emissions.

The EHR system uses exhaust gas heat to warm the engine coolant at start-up. This reduces the time the engine needs to warm up, allowing it to be shut off earlier for longer electric motor-only operation, particularly in winter. As a result, the RX 450h achieves an increase of more than 30 per cent in cold weather fuel efficiency compared to the RX 400h.

The new power control unit (PCU) is smaller and weighs less than before and is equipped with a new inverter. The inverter’s construction allows for cooling on both sides and this better cooling efficiency has helped increase the power density by 40 per cent. PCU power losses have also been reduced by more than 10 per cent to contribute to better fuel economy.

Although power from the front and rear electric motors remains the same as it was on the RX 400h, at 165bhp ( 167 DIN hp) and 67bhp (68 DIN hp) respectively, the improved cooling of the PCU has increased their continuous maximum torque band width. This gives better performance, in particular from a standing start. The front and rear motors now deliver maximum torque of 335Nm and 139Nm from zero rpm respectively, while the range of the front motor’s maximum toque is extended by 9mph and that of the rear by 22mph.

Several improvements have been made to the compact transaxle. An oil slinger has been adopted to reduce drive losses in the oil pump; an oil cooler has been fitted; low friction bearings have been installed at key points; and numerous components have been tuned and re-profiled. These modifications combine to increase torque capacity and overall transaxle efficiency.

An improved flywheel damper, with a two-stage, torque absorbing damper, absorbs torque fluctuations and also the shock of engine stop and start. This significantly reduces vibration and noise, notably in urban driving when the engine stops and starts most often.

Artificial Intelligence AI-SHIFT control has been adopted for the first time on a hybrid vehicle. The system determines whether the vehicle is travelling up or downhill by comparing vehicle speed with accelerator pedal angle. The transmission then selects the appropriate shift range – from third to sixth – to maintain engine rpm at an optimum speed for either uphill acceleration or downhill engine braking.

Sequential shift-matic control is also available, by selecting ‘S’ in the transmission shift gate. In this mode the driver can select any of six speeds to gain more responsive performance, or to add engine braking assistance. The fuel efficiency and performance of the RX 450h’s hybrid drive system are both further improved by the adoption of three new driving modes: ECO, EV and SNOW.

Linked to an indicator in the speedometer, the new ECO mode provides a modified, non-linear throttle action and air conditioning control to support fuel-efficient driving. The relationship between accelerator pedal movement and system output is automatically controlled to reduce throttle response to aggressive driver inputs, improving fuel economy and promoting smoother driving. The air conditioning load on the engine is also reduced sharply under acceleration, further adding to fuel efficiency.

Activated by means of the Multi-information switch on the steering wheel, EV mode allows the RX 450h to be driven under electric motor power alone. This driving mode is not available to drivers of mild hybrid vehicles; it requires a full hybrid technology such as Lexus Hybrid Drive. In EV mode the vehicle can be driven around town with minimal noise and zero emissions, with driving range determined by the level of battery charge. As the petrol engine is switched off, the EV drive mode contributes to a significant reduction in overall fuel consumption.

SNOW mode, also selected with the Multi-information switch, helps modulate use of the accelerator pedal and improve vehicle stability when pulling away on snow or other slippery road surfaces. Pedal inputs are automatically adjusted to reduce driving torque and minimise wheelspin; should there be any wheelspin, the rear electric motor engages to improve traction.

In line with the RX 450hs chief engineer’s vision of ‘Confident Drive’ the RX 450h sets new standards in crossover handling and driving enjoyment. It offers the comfort and composure of a premium saloon, combining responsive handling and agility on winding roads with stable, tenacious four-wheel drive off-road performance.

An all-new bodyshell with high torsional rigidity gives the RX 450h a 20mm increase in wheelbase and 60mm increase in track compared to the RX 400h. Larger, 19-inch wheels improve stability, reduce body roll and contribute to superior NVH performance. The engine is positioned lower, dropping the vehicle’s centre of gravity and improving weight distribution.

The RX 450h has all-new rear suspension and a significantly revised front suspension, which improves its dynamic abilities without sacrificing Lexus’s legendary ride comfort. The design of the rear set-up maximises loadspace volume and practicality. The front MacPherson struts gain new shock absorbers and revised geometry, springs and stabilisers. The diameter of the front anti-roll bar has been increased, improving cornering stability.

The RX 400h’s strut-type rear suspension has been replaced with a new trailing arm, double wishbone configuration that features high-tensile pressed steel components that are lightweight but highly rigid. The system’s wider arm span and rigid trailing arm and carrier joints contribute to a high level of agility and stability, while careful attention to packaging, including locating the springs under the vehicle floor and low, angled shock absorber mountings, minimises suspension intrusion into the luggage floor. As a result the loadspace floor width has increased by 150mm.

January 2011

Lexus has fettled a special Lifestyle version of its RX full hybrid SUV for the some of the rigours of winter with a package of accessories perfectly suited for those who love the great outdoors.

* Special specification for Lexus RX 450h SE-I with package of practical accessories
* Exterior elements include roof rails, front and rear under-runs and rear bumper protector
* Interior features include cool/hot storage box and boot liner
* Value of accessories £1,500 but price premium to customers over standard SE-I model just £499
* Available to order now, from £48,899

On the outside the new Lifestyle model comes equipped with roof rails and a rear bumper protect, plus front and rear under-run plates. Inside there is a tough boot liner ready to cope with muddy boots, plus a refrigerated cool box that can equally keep food and drinks warm when the temperatures plummet. Specified individually, these features would cost up to £1,500, but brought together for the new RX 450h SE-I Lifestyle they add just £499 to the on-the-road price, which is from £48,899.

May 2012

New look for Lexus RX 450h

With higher equipment specifications and a new F Sport model. Styling changes are led by the spindle-shaped grille that is a new trademark element in new Lexus design. In the cabin small but telling tweaks have been made to trim details and the shape and functionality of some of the controls. There is a new steering wheel, incorporating a new selector switch for the hybrid system’s drive modes, and the operation of the Remote Touch controller has been revised so that it works more like a computer mouse. Attention to detail even extends to increasing the opening angle of the centre console box lid to make it easier to reach items inside.

F Sport stands out with a deeper, more vertical front bumper and a dedicated mesh treatment for the upper and lower grilles, which together make the new spindle grille shape an even stronger feature. There are also dark-finish 19-inch alloy wheels and F Sport badging on the exterior, while in the cabin the model’s distinctly sporting character is reflected in aluminium-effect sports pedals and trim inserts, F Sport smooth leather upholstery and scuff plates with the Lexus logo in black. There is also a black roof lining and a bespoke steering wheel with a stitched leather trim.

Other equipment features include a head-up display, and LED headlights with the I-AFS adaptive system that angles the light beam in line with the vehicle turning angle through bends and at junctions. The new RX 450h F Sport also offers sharper driving dynamics thanks to a lateral damper system that increases stability and improves ride comfort by absorbing small vibrations.

The system uses a front lateral damper in place of the usual fixed bracing between the left and right suspension towers. A second damper unit is deployed at the rear, connecting each side of the lower back panel. The units are designed like a monotube suspension damper and adjust in line with changes in the body rigidity, noise and vibration of their surroundings to give the best possible absorption of body torsion, flexure and fine vibrations.

The RX 450h gains an additional Sport mode for itsLexus Hybrid Drivesystem. Selecting Sport (using the new drive mode switch on the redesigned steering wheel) modifies the throttle and electric power steering settings to gain faster responses, and also programmes the Vehicle Stability Control and traction control for less intrusive operation, letting the driver fully exploit the car’s dynamic abilities.

The shift to Sport mode is reflected in the ambient illumination of the instrument panel changing to red.Lexus has revised equipment specifications across all RX 450h, in addition to introducing the new F Sport.

The RX 450h SE entry point to the range gains LED daytime running lights, a new perforated leather upholstery and re-designed steering wheel, while the Luxury grade model adopts (in addition to the above) dark-finish 19-inch alloy wheels and benefits from an upgrade to its 12-speaker audio system with aDABdigital tuner and single-discDVDplayer.

At the top of the range the RX 450h Premier is newly equipped as standard with a tilt/slide sunroof and head-up display.

Three new exterior colours have been added to the range: Satin Silver, Burgundy Red and Atlantic Blue, available for all versions, including the new F Sport.Two new accessory packs have been introduced for RX 450h, offering a range of practical features and styling elements. The Lifestyle Pack offers front and rear under-run protective plates and roof rails, and the new Protection Pack provides rubber floor mats, protective bumper film, mudflaps and a cargo net.

No changes to the hybrid powertrain. Power output is the same 295HP as before, with emissions of 145g/km. Besides the tweaked styling and improved interior, more standard equipment is on offer, including a new power tailgate and iPod/ Aux in for all models. The new F Sport model gets a very slight power tweak to 300HJ.

August 2014

Lexus RX 450h Advance launched

Lexus has released a new RX 450h Advance, a model with a higher equipment level than before including a Mark Levinson premium 7.1 surround sound system as standard.

Despite the additional benefit of the audio package (that has a £1,000 list price) and a set of new-design machined and shaded 19-inch alloy wheels, the price for the new Advance is unchanged, matching its predecessor at £48,495.

The Mark Levinson system provides exceptional audio performance from its carefully engineered array of 15 speakers, including a 200mm subwoofer. These support an exceptionally wide frequency range to give precise reproduction of vocals and instrumentals.

The package also includes a DVD player rear-view camera and Lexus’s intuitive computer mouse-like Remote Touch audio and navigation control system. Lexus Premium Navigation and Bluetooth for hands-free phone calls and audio streaming are also provided. The price tag also includes the choice of either a sunroof or fixed panoramic roof.