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.