The RX 450h will become the catalyst for an all-hybrid European line-up, taking advantage of tax benefits and cost incentives for green vehicles.
However in Australia, the RX 350 will also be available from the first quarter of 2009, boasting a DOHC 3.5-litre V6 petrol engine which develops 204kW.
This figure is outshone by the petrol-electric RX 450h model which uses a new 3.5-litre V6 Atkinson-cycle engine for optimum fuel efficiency.
Total power output from the combined petrol and electric motors is expected to be around 220kW - this is 20kW more than the outgoing 3.3-litre hybrid V6 from the current generation model.
Both models are mated to an electronically controlled, sequential-shift six-speed transmission, replacing the five-speed automatic of the previous model.
Lexus has also made major improvements in its Lexus Hybrid Drive System, including an exhaust heat recovery system which reduces engine warm up time, allowing the petrol motor to be switched off earlier, more often and for longer periods to improve fuel economy and emission control.
While they may look similar on the outside, each model uses a different all-wheel drive system.
The RX 450h's drivetrain uses a rear mounted electric motor generator which allows all four wheel wheels to perform regenerative braking, charging the hybrid battery more effectively.
The RX 350 features an Active Torque Control system, which optimises torque depending on driving conditions.
All models in the new RX range will feature ten airbags as standard, as well as active safety features such as Dynamic Integrated Management (VDIM), Pre-Collision System (PCS) and Intelligent Adaptive Front Lighting System (AFS).