By Samuel Ee

WHEN creating luxury hybrid models, Lexus engineers invariably focus on outright performance rather than the fuel-sipping virtues of a petrol-electric hybrid.

So it's no surprise that the Japanese luxury carmaker calls the Lexus GS450h the world's first performance luxury hybrid sedan. Based on the mid-sized GS sedan, the GS450h has a 3.5-litre V6 petrol engine harnessed to the now well-known Lexus Hybrid Drive system.

This sophisticated technology has already appeared in petrol-electric versions of the RX sport-utility vehicle and LS luxury limousine, both of which are all-wheel-drive.

The GS450h is rear-wheel-drive though - just like the conventional GS300 saloon. But its raison d'etre is identical - to provide the flexible and linear performance of a V8 but deliver the fuel efficiency of a car two segments below. And one more thing - it will have a driving range of over 800 km under a combined cycle, or Singapore to Kuala Lumpur and back on just one tank of gas.

The GS450h's hybrid system is supposed to allow the 3.5-litre V6 engine to perform like a 4.5-litre V8 unit but with the fuel consumption and low emission of a 2-litre V6. Specifically, Lexus lists its actual combined cycle mileage at 7.9 litre per 100 km, or an amazing 12.6 km per litre.

The car's petrol engine is hooked up to two motors - one generating electricity for storage in a high-voltage battery and the other to drive the rear wheels. The kinetic energy of the car is converted into electrical energy and stored in the battery whenever the car is braking or decelerating. With the hybrid powertrain, the petrol engine's maximum output of 292 hp is boosted to a combined 339 hp.

So even before it is launched here next week, the new Lexus GS Hybrid is certain to have one special quality - stonking torque. As a result, there should be loads of driving fun.

Acceleration will be powerful but it will still cost you less at the pump than conventional models offering similar performance. At the same time, the GS450h will have the famed Lexus trademark of a smooth drive and a hushed cabin.

The GS Hybrid will also be introduced with a couple of new features. One of them is the Adaptive Variable Suspension (AVS) first seen in the GS300. This active suspension system modulates suspension and steering characteristics depending on the driver's inclination.

Another is Variable Gear Ratio Steering (VGRS), which debuted in the LS600h L. It controls the turning angle of the front wheels according to vehicle speed. This electronic system means less steering effort is required at low speeds while mild vehicle response is provided at high speeds.

The GS450h also boasts the latest-generation Vehicle Dynamics Integrated Management or VDIM system. To enhance performance, traction control and vehicle stability, VDIM integrates functions like the ECB (Electronically Controlled Brake) system, ABS (Anti-lock Braking System) with EBD (Electronic Brake force Distribution), BA (Brake Assist), TRC (Traction Control) and VSC (Vehicle Stability Control). With VDIM, a skid or slide is anticipated and the situation corrected with a combination of braking, throttle and steering control.

But better than all these latest hi-tech features has to be the financial incentive for buying a hybrid.

With the Green Vehicle Rebate, the GS450h gets 40 per cent of its open market value (OMV) knocked off registration taxes, or a saving of about $26,000. In these current economic times, potential buyers may consider this news simply electric.

This article was first published in The Business Times on Nov 15, 2008.