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LEXUS GS450h

by CAR magazine on 10/09/2008

Comments: 0

AT A GLANCEPrice |R650 000 approx 0-100 km/h |6,18 secs 100-0 km/h| 2,98 secs Top speed| 251 (limited) km/h Economy |9,48 litres/100 km Luggage| 248 dm3 Airbags |10
Ian McLarenUnlike other hybrids to date, the GS is already an accomplished vehicle before all the clever bits were added
John BentleyA truly superb car, not only to massage one’s social conscience, but to drive as well –
Mike MonkAn impressive drive made more satisfying by the hybrid technology
Sudhir MataiQuite a triumph of seamless technological integration, and man does it go
ROAD TEST
SCORE
19/20

THERE is something uplifting, it has to be said, about being able to drive one of the best executive saloons around in the knowledge that you are helping to further automotive technology by being environmentally conscious.

Smug, some may call it, but in the case of the Lexus GS450h hybrid, that would be unfair, because here we have a luxury car with the performance of a V8 and the economy of a diesel that, consequently, means its emissions impact on the atmosphere is far less than that of its conventionally powered peers. As an example of petrol/electric development, the GS450h represents a partial but viable solution to the automotive world's current dilemma of finding an alternative means of propulsion for the near – for which read 15 to 20 years – future.

But let us start with the basics. Introduced to SA in June 2006 and upgraded in May 2008, this (actually third generation) GS is already a winner – the petrol-fuelled GS300 was voted CAR's 2008 Top 12 Best Buy in its category. A shining – particularly when sprayed in the test car's pearlescent white – example of Lexus's L-finesse design approach, the GS is an imposing vehicle that casts a large shadow: it is 4 850 mm long and 1 820 mm wide, with a wheelbase of 2 850 mm, which translates into a cabin spacious enough to transport four adults in appropriate style and luxury.

However, the traction motor's battery pack takes up some boot space, reducing the volume to 248 dm3, which is small but still golf-bag friendly.

From the outside, the fact that the GS450h is a hybrid is not readily apparent. The boot badge is a hint to those in the know, leaving the "hybrid" badging on the sills to subtly point out to anyone entering that they are stepping into a car that is different from the norm. The leather upholstery and wood and metal finishes have been carefully blended to create a quality-built interior that is conservative in layout and somewhat sombre in ambience, but nevertheless exudes class. Both front seats have all-electric adjustment, including lumbar, with a threeposition memory that for the driver includes steering wheel and exterior mirror settings.

When switching off, the wheel rises to ease entry/exit.

Being a Lexus, the features list is comprehensive and what you see is what you get. However, given its line-up of standard equipment, there is hardly any- thing missing that could be considered an "absolute must have" at this level. Ten airbags form part of an extensive safety specification.

But there are a couple of minor features on the car that make it appear a bit old-fashioned when compared with its rivals: the absence of one touch/ three winks indicators, and manual height adjustment for the front seatbelt upper mounting point. Nit-picking perhaps, but Lexus generally sets such a high standard… It is only when pressing the "power" start/stop button that the GS450h's "futuristic" modus operandi reveals itself. The centre facia display screen springs into life to reveal a schematic diagram showing the engine, electric (traction) motor, battery and wheels. Engage the transmission, release the (horrid) foot park brake, depress the accelerator and pull away… Controlled by the powertrain's PCU (Power spellbinding stuff to any motoring enthusiast. With full-bore acceleration, the two motors combine to produce an effective maximum 254 kW, the needle whipping right around the dial and staying put until cruising speed is attained. On the other hand, it is interesting to see just how little power is required to maintain modest momentum. You soon learn the effect a heavy right foot can have…

The GS450h is the first production full-hybrid with rearwheel drive. It is also billed as the first performance hybrid, eschewing the more obvious single-minded focus on simply being eco-friendly – "green" if you prefer. "Performance with a conscience" is Lexus' Hybrid Drive philosophy, an understandably more gutsy approach than that of owner Toyota's parallel development, Hybrid Synergy Drive, as found in the ground-breaking Prius. Performance? Well, in the case of a petrol/electric hybrid, the electric motor fulfils the role that a turbo- or supercharger does on a regular powertrain, with the advantages of no lag or mechanical drain: maximum torque is delivered from the moment the armature starts turning. And an electric motor is unaffected by altitude. So, the benchmark 0-100 km/h sprint takes 6,18 seconds, which is rapid no matter what lies under the bonnet. With the 147 kW water- and oil-cooled electric motor providing its 368 N.m of maximum torque from zero revs, and the petrol engine building on its 218 kW of peak power to develop 368 N.m at 4 800 r/min, the near-1,9 ton GS is clearly no slouch. Coupled with a six-step, two-stage electronically controlled CVT transmission, kick-down will accelerate the car from 60 to 120 km/h in 5,65 seconds. Aerodynamically efficient – its drag coefficient is an admirable 0,27 – the GS's top speed is limited to 250 km/h.

But the major benefits of a hybrid are economy and emissions, and here the GS450h's raison d'etre reveals itself. Bear in mind this is a large and heavy performance car, so the fuel index, ie overall petrol consumption, of 9,48 litres/100 km is extremely impressive. And this equates to a CO2 emissions figure of 248 g/km, around 25 per cent less than with a big V8 petrolengined saloon of similar stature, and about 15 per cent more than an equivalent turbodiesel. So the hybrid really does offer the best of both worlds – see the Rivals panel for a comparative picture.

And the more in-town (where atmospheric pollution is at its greatest) driving that is done, the more beneficial is the effect. With all this wizardry to marvel at, it is easy to overlook such mundane matters as ride and handling.

Here, again, the Lexus proves to be above average. Riding on 18-inch rims with substantial 245/40 tyres, the GS rides extremely quietly and serenely on firm but compliant suspension, the dampers of which can be stiffened for a more sporty feel at the flick of a console switch. The Lexus' electric steering is one of the better set-ups we have experienced, and with 2,7 turns from lock to lock allied with a modest 10,7 metre turning circle, it makes this large car surprisingly manoeuvrable. Ventilated discs all round with fullhouse ABS control provide ample stopping power.