The Lexus RX 400h is the world’s first premium SUV to feature a hybrid power system. It achieves a unique position in the market by not only delivering the low exhaust emissions and high fuel efficiency that are well-established characteristics of hybrid power, but also by providing the high performance that has until now typically been the preserve of large-capacity petrol engine models.

In spite of its use of a wide range of advanced technologies, the RX 400h remains true to all the core principles of Lexus with no compromise in terms of luxury, quiet and seamless operation, durability and refinement.

The RX 400h’s Hybrid Synergy Drive® system combines a 3.3-litre V6 petrol engine with a 165bhp front electric motor that has a world’s-best power to weight and volume ratio, a high voltage battery and a generator. A second electric motor at the rear axle gives the vehicle an electric four-wheel drive capability — E-Four — that is automatically engaged when required.

In any journey, the system will operate in different modes in order to maintain the maximum efficiency, with power from the engine, the electric motors or a combination of both. Whenever the vehicle comes to a halt, the engine will automatically be switched off to minimise fuel consumption.

The RX 400h can run on its electric motors alone at start-up and low to mid-range speeds, which cuts exhaust emissions to zero. In normal driving conditions, a power split device will divide output from the engine between driving the wheels and powering the generator, which in turn charges the high-voltage battery. This means the vehicle never has to be off the road to be charged.

Further energy is gained during braking or deceleration with the electric motors operating as high output generators to recover kinetic energy that would usually be lost as heat and storing it as electricity in the high-voltage battery.

Maximum output from the Hybrid Synergy Drive® is 269bhp, which gives the RX 400h a top speed of 124mph and 0-62mph acceleration in 7.6 seconds. Progress is seamless, thanks to the electronically controlled Continuously Variable Transmission (E-CVT). In official combined cycle driving the vehicle returns 34.9mpg, a better figure than any of its premium petrol SUV rivals and on a par with the very best diesel performance. In terms of exhaust emissions, the vehicle complies with Euro IV emissions standards and produces 192g/km of carbon dioxide. Nitrogen oxides emissions are reduced to near-zero.

The RX 400h is the first SUV to benefit from Vehicle Dynamics Integrated Management (VDIM), a Lexus-developed system which coordinates operation of the ABS, Electronic Brakeforce Distribution (EBD), Traction Control (TRC) and Vehicle Stability Control (VSC) to maximise their performance capability.

VDIM triggers the systems when it detects the vehicle is nearing the limit of its performance, instead of them coming into play individually when that limit has been reached. This means their intervention is less obtrusive and the vehicle is kept under control more smoothly.

VDIM also integrates the electric power steering system, adjusting steering torque to make it easier for the driver to return the vehicle to the correct course. The RX 400h is equipped with a ‘by-wire’ electronically controlled brake system (ECB) and brake assist (BA).

To improve the driver’s vision through bends, SE and SE-L versions of the RX 400h are equipped with an Adaptive Front-lighting System (AFS). This swivels the headlamp beam in accordance with vehicle speed and turning angle in order to provide better illumination.

All versions of the RX 400h are equipped with nine airbags as standard. These include a driver’s knee airbag and large capacity Thorax-Abdomen-Pelvis side airbags.

The RX 400h is almost identical to the RX 300 model, sharing the same aerodynamically-efficient design that provides excellent stability and keeps wind noise levels to a minimum. A few details set the RX 400h apart, including a revised front grille designed to aid cooling of the Hybrid Synergy Drive® system and neatly integrated front fog lamps in the front bumper section.

The high voltage battery has a compact three-section design, which has allowed it to be located beneath the rear seats without compromising passenger space in any way.

The driver can monitor the drive system’s performance from a power meter that replaces the tachometer on the central instrument display. On versions equipped with the Lexus Navigator satellite navigation system (standard on SE-L, optional on SE models) the power flow can be displayed on the seven-inch colour monitor on the centre console.

In the UK the RX 400h is offered in three grades: RX400h, SE and SE-L. The entry-level specification includes cruise control, multi-zone climate control, eight-speaker sound system with dashboard-mounted six-disc CD autochanger, rear privacy glass, High Intensity Discharge (HID) headlamps and electrically adjustable front seats.

SE models further benefit from leather upholstery, automatic wipers and lights, an electric sunroof, power-operated tailgate, electric steering column adjustment, Adaptive Front-lighting System (AFS), 40:20:40 folding rear seats, heated front seats and memory settings for the driver’s seat, mirrors and steering column.

The SE-L grade includes the Lexus Navigator satellite navigation system with touch screen operation, voice control capability and Electronic Traffic Avoidance. This system brings with it Bluetooth® connectivity which permits hands-free use of compatible mobile phones, and the Rear Park Assist Monitor which transmits the view from the back of the vehicle to the colour monitor on the centre console for safe and simple reverse parking manoeuvres. SE-L versions are also equipped with state-of-the-art in-car entertainment, including an 11-speaker Mark Levinson® premium hi-fi and a DVD player with twin monitors mounted in the back of the front seat headrests. The Lexus Navigator package is optional on SE models; the ICE DVD system is an option on the RX 400h entry-level and SE models.

The RX400h starts at £35,485, with the mid-range SE model at £39,540 and the range topping SE-L at £44,350.

The RX 400h is offered in seven colours: St Lucia Pearl, Platinum Ice, Aleutian Grey, Astral Black, Persian Quartz, Cherwell Green and Stafford Blue.

Lexus designed the RX 400h to deliver low cost of ownership in terms of standard maintenance requirements, paying close attention to component durability and competitive parts pricing.

As a result, the labour time for standard servicing during the warranty period of three years or up to 60,000 miles amounts to 5.2 hours, just the same as for the conventionally-powered RX 300 model, demonstrating that the RX 400h’s hybrid technology does not bring higher maintenance requirements.

Sales of premium segment SUVs have consistently been split 70 to 30 per cent respectively between private and corporate sales. In terms of fuel preference, the market is dominated by diesels, which have maintained a segment of around 66 per cent. Among petrol engine vehicles, those of 4.0 litres or less account for almost 25 per cent of segment sales, while less than 10 per cent have larger capacities.

The new RX 400h is positioned to claim sales in both the high-power petrol and the diesel sectors, thanks to the strong balance of power, high torque and efficiency delivered by its Hybrid Synergy Drive® system. It also has the potential to draw new customers to the SUV market, as it is the only luxury vehicle currently to offer such a technologically advanced powertrain.

In terms of fleet business, Lexus is targeting 65 per cent of RX 400h sales to be to corporate customers, compared to 15 per cent for the existing RX 300 model. This reflects the vehicle’s strong BIK tax position compared to its rivals. The SE model is rated at 23 per cent for BIK in 2005/6 and 22 per cent in 2006/7, bringing annual company car tax bills of £3,
615 and £3,548 respectively. The RX 400h will allow Lexus to make a considerable step into the Corporate / Fleet sector.

The RX 400h is on sale in the UK from 15 June with a sales target for the remainder of 2005 of 1,625 units, rising to 3,850 in the full year 2006.