ATHENS is a wonderful city. Its amazing mix of classical architecture with indiscriminate 20th century urbanisation makes for fascinating touring, viewing and sheer wonderment.

Yet, the authorities have been unable to master one major problem: traffic. It's excessive, noisy and creates a gridlock on every street, and worst of all overloads the atmosphere with noxious fumes.

So, when it comes to unveiling a new hybrid petrol/electric car there could be nowhere else better, in Europe that is, than Athens as its launch pad.

Lexus took its new RX400h sports utility there, where its dual petrol/electric engine added virtually nothing to the contaminated atmosphere, even when shuffling along in traffic or waiting in jams.

The hybrid combines a V6 petrol engine with front and rear electric motors to help the wheels go round. In fact, running on purely electric power, the RX is ideal for city use, when it simply whispers along, causing no noise pollution either. Silent pick-up from rest is the standard thing anyway, with the petrol engine chiming in later as required.

With an on-the-road price starting at £35,485, the RX is the world's first premium sport utility vehicle or SUV to feature a hybrid power system.

Although basically a re-engineered Lexus RX300, a few details set the RX400 apart, including a revised front grille specially designed to help keep the hybrid synergy drive system cool, and neatly integrated front fog lamps in the front bumper section.

The RX400h's drive system combines a 3.3-litre V6 petrol engine with a 165bhp front electric motor, a high voltage battery and a generator. A second electric motor at the rear axle gives the vehicle an electric four-wheel drive capability (called E-Four) that is automatically engaged when required.

On versions equipped with the Lexus Navigator satellite navigation system (standard on SE-L, optional on SE models) a dashboard display tells you when the car is in petrol mode, when it is battery-powered, and when it is both.

It also lets you know when power is being captured and stored in the battery as the car coasts or brakes, a system that means the car does not have to be taken off road to be recharged.

Whenever the vehicle stops, the engine automatically switches off, saving fuel and automatically cutting off any nasty emissions.

The RX can run on its electric motors alone at start-up and low to mid-range speeds, which also cuts exhaust emissions to zero.

It uses a constantly variable transmission, which doesn't have separate gears, so there are no kickdown or shift-point jerks.

The RX has a top speed of 124mph and a 0-62mph acceleration time of 7.6 seconds.

Once out of the city and on to more open roads, you really can feel the car getting a helping hand from the electric motors. It is especially noticeable in the midrange. The extra shove you get for overtaking from, say, 40 to 50mph feels more as if it is from a V8 than a V6.

In official combined cycle driving, the vehicle returns 34.9mpg, on a par with the very best diesel performance. The RX400h is fitted out with a special Lexus-developed vehicle dynamics integrated management system, which coordinates various operations including anti-lock braking, electronic brakeforce distribution, traction control and vehicle stability control and prepares them for action when it detects the vehicle is nearing the limit of its performance.

The RX 400h is equipped with a "by-wire" electronically controlled brake system and brake assist. Incidentally, the parking brake is foot controlled, so no hand lever.

To improve the driver's vision through bends, SE and SE-L versions of the car have been fitted with an adaptive front-lighting system. This swivels the headlamp beam on cornering so throwing light into dark bends.

All versions of the RX400h are fitted with nine airbags as standard.

In an otherwise unfussy cabin, the high voltage battery is hidden beneath the rear seats without compromising passenger space in any way.

The entry level RX400h 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 headlamps and electrically adjustable front seats.

The SE models add leather upholstery, automatic wipers and lights, an electric sunroof, power-operated tailgate, electric steering column adjustment, the adaptive front-lighting system, 40:20:40 folding rear seats, heated front seats and memory settings for the driver's seat, mirrors and steering column.

Flagship SE-L models have the Lexus Navigator satellite navigation system with touch screen operation, voice control capability and electronic traffic avoidance (of little use in Athens!); Bluetooth connection, and a rear park assist monitor which provides a nice picture of anything hidden behind the car when reversing. The SE-L versions are also kitted out 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.

At a glance:

Models, prices, insurance band: RX400h £35,485 16E; RX400h SE £39,540 16E; RX400h SE-L £44,350 17E.

Maximum power: 208bhp at 5,600rpm; maximum torque 288Nm at 4,400rpm

Performance: 0-62mph 7.6-seconds; top speed 124mph)

Economy: Combined 34.9mpg, extra urban 37.2mpg, urban 31.0mpg.

Dimensions: Length 4750mm, width 1845mm, height 1720mm, wheelbase 2720mm.

Dealer: Lexus Hull, Priory Park, Saxon Way, Hessle, East Yorkshire (phone 01482 333222)

Updated: 12:51 Friday, June 17, 2005