Road Test: Lexus GS450h

By Feann Torr - 25/Oct/2006

The hybrid idea is a gallant one: use an electric motor in tandem with a petrol engine to reduce fuel consumption, of which lowered C02 emissions are a positive side-effect. Lexus aims to go one better with its new range of hybrid luxury vehicles, where the goal is to keep fuel consumption low, without putting the brakes on performance. 

Can it be done effectively? 

Lexus has proved that it can be done with the GS450h, and it's an extraordinarily impressive car to drive. The asking price, slightly more than $120,000, may sound a bit steep but like all Lexus vehicles, it packs a serious amount of standard hardware, including 10 airbags, radar cruise control, a 14-speaker premium audio system, a rear view camera, plus a pre-collision detection system and arguably the most powerful electric engine available for public consumption.

Meanwhile companies like BMW, Mercedes and others whose cars are already out of reach for a majority of car buyers have yet to offer anything in the realm of low emissions vehicles, other than concept cars that are simply that - concepts. Lexus, however, is forging ahead with real world solutions to reducing exhaust emissions and it's pleasing to see. 

And for every advancement that Lexus and it's parent company Toyota make in hybrid technology, it will make future propulsion systems all the more achievable, because much of this gained knowledge in hybrid cars will benefit future fuel cell vehicles. Hydrogen may be the fuel of choice in 20 years time, but electric generators will likely be key aspects of such propulsion systems.

This new fangled high-performance GS450h hybrid luxury car will "revolutionise the automotive landscape" according to Lexus, and rather than having a petrol combustion engine, this vehicle has a 147kW electric motor as well as a 3.5-litre V6 engine. But having heard such statements dozens of times before, I treated this "revolutionary" catch-cry with a good deal of circumspection before I sat down in the vehicle and physically drove it. 

The burning question - is this vehicle really going to revolutionise the automotive landscape? Let's find out:

Drive: 4.5/5

"Who stole the tachometer?" I thought to myself after setting up the rear view mirrors, steering wheel position and plush leather driver's seat - all electrically controlled, naturally.

"That's a power meter," pointed out one of the resident Lexus mechanics, which indicates how much power the car is generating (up to 250kW). 

Indeed, this is one of first clues as to the GS450h's impressively advanced hybrid system, which is capable of outputting 254kW to the rear wheels. But don't be scared - this isn't the kind of vehicle that must be carefully studied, researched and unequivocally understood to extract maximum operating efficiency. 

You never need charge it, nor tend to it in any other way - you just put the car in drive and off you go. Simple as that.

You needn't even put a key in the ignition barrel - the car's proximity sensors will detect the key fob in your pocket and unlock the car and allow you to start it, and it's the smaller touches like these that contribute to ensuring this car elicits curiosity like few others.

Like many modern luxury cars, one of the first things I savoured (after eying off the surfeit of knobs, buttons and switches scattered around the driver) was the accommodating driver's seat. I think the word opulent is justified here, and with few pointers from the Lexus blokes before driving off - such as the fact that you'll never hear the thing start because it initially sparks up the electric motor - I slowly took off down the road.

Being a true hybrid, the GS450h can run purely on electricity, purely on petrol, or a combination of both. And it wasn't long before I wanted to see if the Lexus claim of performance was truth or PR hyperbole. 

I couldn't help it - I stuck the boot in.

Not only was I impressed with the instant torque hit, followed by seriously strong acceleration, but the smoothness and refined feel of the whole package was palpable. And it wasn't until half-way through my week long test that I realised the GS450h uses a step-less gearbox. Indeed, the advanced CVT (continuously variable transmission) goes a long way to improving the car's fuel efficiency and performance, and along with transmissions like Volkswagen's DSG, it's clear to see where the future of the automobile power transfer lays.

Returning a claimed fuel consumption of 7.9L/100km, the Lexus is as quick as it is frugal, and uses an electronic CVT to provide peak power and torque instantaneously. By the same token, the car is advanced enough to run totally on electricity, meaning the petrol engine shuts off and you consume zero fuel. I managed to coax the car up to about 50km/h in this mode from standstill, and more than anything else it's the eerie silence that astounds (and the fact that pedestrians use their hearing more than their sight to decide whether to cross the road - had some close calls there!).

Being a luxury car, it's got everything you'd ever need to for almost every sealed road situation. The CVT makes for a completely seamless driving experience - there are no steps between gears, because the transmission is constantly engaged. This makes the slow moving commuter drudge far more bearable, and thanks to the shit-hot 14-speaker Mark Levinson stereo system and myriad other distractions - such as the class-leading sat nav - you'll never be completely bored, left to daydream of sandy beaches or sub-tropical rainforests as the motorist behind you begins to assail you with blue language.

Proximity sensors are located at the front and rear ends of the vehicle, and operate constantly, not just when reverse is engaged or speeds drop below 10km/h. Though sometimes annoying (such as when at the traffic lights, when pedestrians walk past) it's also very reassuring, as you'll know when another car is getting too close in peak hour traffic jams, for example. Moreover, parking an 4.82 metre long and 1.82 metre wide vehicle that costs a pretty penny (and isn't yours...) can be an especially harrowing experience, but because all its proximity sensors and the reverse camera are standard features, it's a doddle to squeeze into tight gaps. There's even a very helpful overlay system on the LCD reverse camera screen that simulates where the car will be when given a specific amount of steering lock, which is not only helpful, but will seriously impress your mates.

And when you finally hit the open road to stretch the car's considerably long legs on the highway, there's a very practical radar-based cruise control system that works wonders. It has three settings (close, medium, far) and warns you when you get too close to the car in front, both visually and audibly. I found it to be a fairly effective system in reducing throttle and even braking the car automatically if it detected the vehicle in front slowing, though when it attempts to regain speed it does so with such lethargy that I often found myself cursing its computer brain. The upshot is you never really need touch the throttle as the Lexus will accelerate back up to your chosen speed when the coast is clear, and unless you're in a great hurry it works quite well.

Generally speaking, the car has very good road manners. It is easy to handle in built-up areas with a variable steering system, so even when you're cruising slowly, whether looking for a car park or just obeying speed limits, the steering is responsive and direct, and around town the ride it's nice and soft, kind of like a canal barge, and there's not too much road noise due to impressive audio insulation hidden in the body.

In busy urban driving conditions, the car is easy to guide along the road, with a soft steering feel and a supple ride that can absorb pretty much anything the road may degenerate in to, even when sitting on fairly sporty 245/40 R18 tyres on sizable 18-inch alloy rims. This is due in large part to AVS, or Advanced Variable Suspension, which helps explain why the car has such a supple ride despite the low profile tyres. 

As Lexus explains, the adaptive variable suspension is a "computer-controlled system that continuously adjusts shock-absorber damping rates to help provide appropriate ride comfort and handling precision". Automotive hyperbole? Not really. The system works rather well in most cases, adjusting damping rates on the fly, but does give the mid-sized Lexus a somewhat 'floaty' sensation at times. However, when driving in urban areas and along freeways I found the ride quality to be relaxed and very acceptable.

The AVS system is rather clever, as it monitors areas such as steering-wheel movement, brake application, vertical body motion, wheel speed and engine revolutions (rpm) to determine how soft/hard to adapt the suspension, and there's also a sports suspension button that stiffens everything up for when the road opens and begins to twist and turn. This suspension toggle button - along with driving mode options (power, normal, snow) - is hidden beneath the retractable centre armrest in a feature that feels as though it's come from one of 007's spy cars.

The Lexus GS450h's natural habitat will generally be urban areas, driving to and from work and so forth, but on open country roads and fast mountain passes, this thing has some serious mumbo. When the suspension system is switched to sports the GS450h sits very nicely on the road and is remarkably quick through corners for something with such a luxury pedigree. 

Generally speaking the car does leave the driver feeling somewhat detached from the chassis when one begins to explore the car's cornering limits, with the light steering and CVT gearbox offering little in terms of physical response, but that doesn't discount the fact that it's astoundingly quick through corners and goes like a bat out of hell on the straights.

The brakes worked well enough, ventilated discs measuring 334mm up front, 310mm at the rear, but considering the car's 1865+ kilogram mass (without luggage, passengers, or fuel), they should have been bigger, or at least equipped with stronger calipers and more resilient brake pads. The brake pedal felt rather spongy towards the end a days worth of flogging, and maybe the Lexus didn't envisage drivers punishing the vehicle for 10 hours straight, but hey, don't call it a performance car if you don't want people to 'perform' in it.

Getting back to the switchable sports suspension is very practical solution, because you can cruise around really smoothly in luxury mode and then stiffen it up at the push of a button. It really does handle well round corners in sports mode. Given a squeeze the thing is very quick through a corner with relatively low levels of body roll, though it does have a tendency to push its front inside wheel if you get a bit overzealous, but still maintains a positive attitude when throttling on through a corner.

One of the reasons I believe this vehicle is capable of such impressively high cornering speeds is not due solely to the intelligent suspension system. I reckon tyre choice plays a large part too. 

Arguably the most important performance aspect of the modern motor vehicle, Lexus has been savvy in choosing rather fat tyres with aggressive tread patterns for its hybrid luxury sports tourer. And because of the AVS, the rough ride that tyres measuring 245/40 R18 would normally afford is, for the most part, negated.

The tyres really bite the bitumen hard, and when you're pushing 9/10ths you can hear the tyres beginning to squeal as they roll over onto their side-walls due to increasing lateral G-forces, but it matters not in the heat of the moment - this thing just keeps holding on.

Testament to this car's incredible power and cornering ability is this little anecdote: I was joined by a brand-new 2006 model R32 Golf during a rather exhilarating stretch of coastal driving, and for the most part I was just edging ahead of it through the twisty bits, and comfortably so when the road straightened up. Another thing I noticed when giving the Lexus GS450h a real hammering was that the VSC (vehicle stability control, which is the same as ESP) is remarkably unobtrusive. In many instances the only reason I knew it was operating was because a little ESP light blinked on inside the instrument cluster, rather than feeling any retardation of torque and individual brake applications.

Though there are cars that are quicker to 100km/h from standstill than this, the nature of the electrically-boosted petrol engine in combination with the CVT means that there's no let up in acceleration, and that makes for one very quick luxury car.

Indeed, the extra kick in the cods that the electric motor provides for performance usage is just as impressive as its fuel-saving abilities; it's almost like a turbo push as your body is gently squeezed into the seat cushions, such is the surge of power when petrol and electric motors combine forces. And unlike traditional gearbox designs, where you'll feel the torque pulsing through the gears when the engine reaches its powerband, the GS450h maintains a constant level of shunt that is difficult to describe.

And that's the way it is. Lexus has crafted an incredibly malleable vehicle in the form of the GS450h. It's not a perfect performance vehicle, as there is a feeling of detachment between car and driver when punting it hard, as thevariable gear-ratio steering, or VGRS in Lexus speak, fails to communicate accurately what the front wheels are doing, and the brakes tended to fade with extreme use. But even these quibbles are not enough to dilute its impressive all-round ability, and doesn't detract from its balanced chassis.

When I begin to think about the six figure price tag attached to the car, even that argument goes out the window, because it's jam-packed with the kind of features that would leave BMW drivers slack jawed, such as the hybrid propulsion system, radar-based cruise control, swivelling front headlights, pre-collision detection system, 10 airbags and adaptive suspension. 

It works remarkably well in a number of different driving scenarios, from commuter driving, Sunday market shopping, and (my favourite) Saturday morning sprints through mountain passes.

Acceleration? Handling? Economy? Comfort? You better believe it.

Engine: 5/5

While there were a plethora of systems that piqued my interest in relation to how the GS450h went about its business, from the radar-based cruise control to the front seat-based air-conditioning system, the engine systems are simply mesmerising, with more world-firsts and "are you serious?" features that I've ever witnessed before.

Firstly, the GS450h's engine is comprised of two distinct segments - the 3.5-litre V6 engine and the 650V permanent magnet motor. These two motors are connected to an electronic CVT, or ECVT, that features two sets of planetary gears that can simultaneously (or independently) transfer power from both. What this means is that the Lexus GS450h can run purely on petrol, purely on electricity, or a combination of both - the latter of which provides the car with serious off-the-line acceleration - about 6.0 seconds from 0-100km/h according to our measurements.

As well as being the world's first rear-wheel drive production hybrid car (and yes, it does burnouts - though reluctantly), the Lexus GS450h is also one of the first cars in Australia to feature two fuel injection systems (direct injection and multi-port injection). And if all this technical stuff means nothing to you, then here's a quick translation: the Lexus GS450h has one of the smoothest, most refined, quiet, efficient and altogether powerful engines you're ever likely to drive in Australia.

With a combined petrol/electric power output of 254kW the engine is already a very powerful proposition, and with the added advantage of an ECVT the car is preposterously quick. I was expecting to find a fairly rapid luxury car, but when push came to shove it became clear that this vehicle was capable of accelerating like a rocket. 

Because the ECVT has no gears in a traditional sense - or an unlimited number if you want to view it from another perspective - it will simply rev up to the speed where it produces maximum power (listed as 6400rpm) when given full throttle, while the electric motor adds to this by instantly dumping up to 275Nm of torque into the gearbox. Being an electric motor, it need not rev up - it's torque delivery is instantaneous, and that's how the GS450h achieves its ballistic levels of acceleration: a combination of almost-instant petrol power and 'oh my lord, that's very instant' electric power.

In practice, the car is a delight to drive. It's quiet and refined and creamy smooth in all aspects, and mid-gear roll ons (though the term is not quite right in regards to a ECVT) and overtaking duties are child's play, with even a half throttle application resulting in serious forward movement. If you give the throttle just a light tickle from standstill, the car will remain in electric mode, not bothering to activate the petrol engine and you can monitor exactly what the hybrid system is doing via the LCD touch screen mounted in the centre console (which also displays the rear parking camera, sat nav, and other assorted menus). 

It shows you when the electric motor, the petrol motor, or both combined are powering the rear wheels, and also whether the electric motor is taking energy from the battery supply, or the battery supply is being recharged via regenerative braking or via the petrol engine. It sounds complex because it is, but its operation is incredibly simple. Put it drive, and push the accelerator pedal. It's as simple as that.

The Lexus GS450h is a hybrid, which it advertises on its flanks and rear end and through numerous features inside, which means that as well as offering the hardcore performance that two engines provide, it can also be driven very lightly, and it's at this point that it becomes clear how versatile and down-right awe inspiring this dual engine system really is.

Lexus claims a dual city/highway fuel consumption rate of 7.9L/100km, which is remarkable for something with the sort of grunt under its bonnet. It's about as quick as a big V8 Falcon or Commodore, only far more frugal. As mentioned, I was able to stir the GS450h up to about 50km/h on electric power before the petrol engine kicked in to provide more power, as the electric engine all torque and not much else.

The petrol engine aspect of the hybrid system is a 3.5-litre 60° V6 engine that weighs 177kg and features quad camshafts with variable valve timing (intake and exhaust), and a sky-high 11.8:1 compression ratio. Even on it's own this engine provides 368Nm of torque and more than 200kW of power, which would be considered more than ample for this sort of luxury saloon.

At the end of the day, the hybrid system contained within the GS450h is incredibly difficult to accurately describe in any technical detail on this page, such is its complexity. The image above goes some way to explaining how the gearbox and hybrid engine system combine into one efficient system, but let me finish by saying it's a mechanical work of art. It's frugal, powerful, refined, and very quiet, which is the epitome of how a luxury car's engine should be. 

This powerful hybrid system is, in a word, magnificent.

Exterior: 3.5/5

When Lexus released it's third generation GS series mid-sized luxury cars in 2005 - rivals to the Mercedes E-Class, BMW 5 Series and Audi A6 range - the look hit me with real force and I was quite taken with the new look. A year or so later and the look isn't quite as mesmerising, but all in all, it's a luxury car with a quietly aggressive demeanour, with enough chromium highlights to ensure everyone around you knows that you're driving a prestigious vehicle.

I liked the front end design with its dual element headlight cluster, and the front apron with its simple grille and lower air dam section are conventional in every sense of the word, eschewing the more daring designs seen in the BMW 5 Series. But despite its more orthodox face, the GS450h is still an attractive car in many ways. Sometimes simplicity can be just as alluring as complexity.

Lexus calls its current design philosophy 'L-Finesse', which according to the company is steeped in Japanese culture, whose aim is to display "...an outward face of tranquility and simplicity with underlying complexity and depth," said Simon Humphries, who is the manager of design strategy at Lexus' Global Design Division. No arguments here.

The overall profile of the car is quite sleek and matched with 18-inches of circular alloy goodness with a triple five spoke design, the effect is quite imposing and befitting of a prestige vehicle. The rear of the GS450h isn't quite as pretty as the front end, with the rear windscreen tapering towards the boot rather lazily, which creates a much stubbier rear end that is in stark contrast the car's long bonnet.

Looking directly at the rear end however, things aren't quite as obtuse. The brake light clusters actually look quite good, and in tandem with a subtle deck lid spoiler there are far worse backsides that you'll see flying past at incredible speeds. Exposed twin exhaust pipes hint at the performance that lurks beneath the Lexus GS450h's smooth skin, and though the car's design could be described as unadventurous, I think that it will ultimately garner favour among the luxury car crowd for this reason.

Interior: 4.5/5

Sitting in the hybrid Lexus is just as it should be for a $120,000+ luxury vehicle - suitably opulent. The high quality leather upholstery, underneath which exists very supportive but soft cushioning, provides both driver and occupants with suitably relaxed seating, and for long distance driving the cushy pews are impressively comfortable with just the right amount of lateral support to be neither over- nor under-done.

And being a high-tech hybrid car, there's a veritable cornucopia of knobs and buttons to mess with. 

Up front there is a dizzying array of controls and the LCD touch screen located in the centre console is the centre piece of the cars features. Lexus calls it an EMV screen, or electro multi-vision screen. Whatever you want to call it (my niece called it a 'puter), it displays things such as the satellite navigation, which is a standard feature on the GS450h, and is easily the best such system I've ever used. It makes the current sat nav systems (which are about to be revised) in BMWs and Audis look completely outmoded.

With it's high-resolution visuals and easy to read fonts, the system is also one of the quickest to input street names and places of interest due to the touch screen technology. No fiddly iDrive/MMI knobs here.

Additionally, the EMV screen can also provide a real-time display of where the hybrid system is doing, and also show you on a graph display how much fuel you've used, and how much electricity you've generated. And because every function is touch screen-based, it makes navigation through menus intuitively straightforward. 

The centre console looks very nice with the bright LCD screen and is nicely laid out and easy to use, but the old-school digital clock that sits atop the LCD screen takes a little away from the technical ambiance, adding a real 1993 sort of vibe. The time is displayed on the LCD screen anyway, so was there need for it?

The instrument dials - power meter, speedometer, fuel level/engine temp - imbue the dashboard with high tech feel, finished in blue and silver, and are recessed back into the dashboard which adds a further, somewhat strange sci-fi feel. General fit and finish is impeccable, particularly on the inside of the doors, and there's even a small fold-out control panel to the right of the steering wheel that contains another dozen or so buttons that control mirrors, adaptive headlights, the rear sunshade and numerous other automatic functions.

General standard features on the GS450h are impressively broad, and include climate control plus power operated and air conditioned front seats where cool/hot air is pumped through the tiny perforations in the front seats, which are surprisingly effective especially after a hot day at the beach. 

There's real wood trim on the dashboard and steering wheel that help create a luxury ambiance, radar-based cruise control, rain-sensing wipers, a rear-vision reversing camera, an electrically operated rear sun shade, 10 airbags, a pre-collision system, electro-chromatic external rear-vision mirrors and a rip-snorting 14-speaker Mark Levinson stereo system with 5.1 surround sound capabilities, CD, DVD, WMA and MP3 playback functions. There's also Blue tooth connectivity for phones and a voice recognition system.

The centre arm rest slides back to reveal a number of driving toggle buttons, such as engine power levels (normal, sport, snow), suspension modes (sports, normal) and the traction control on/off button.

Safety wise, and there's not much more than could be added to this vehicle. Ten airbags (including knee and curtain airbags) are standard, as is the pre-collision system, which can increase the sensitivity of the brake pedal if the car detects a collision is unavoidable. Adaptive front headlights (AFS) are also standard on the Lexus GS450h, as the usuals, including ABS, EBD and VSC (vehicle stability control).

As far as interior space goes, the Lexus is roomy enough. Head room is decent up front, but in the rear the headroom is wanting. Sure, there's plenty of under thigh support and good leg room, and my six foot frame was quite comfy in the rear, but my head was about 1 cm from the roof, and any bumps would see me bashing my noggin, which sounds funny but in reality is not very amusing, and kind of hurts after a while.

In addition to rear seat headroom, the only other real problem I could find with the Lexus GS450h's interior is the boot. It's tiny -- 280 litres in total, which is about enough for a golf bag or two, or maybe a few boxes of fruit from the market. However, this small rear cargo space is a necessary evil because the hybrid's battery system lives between the boot and rear seats. There's a large vent in the rear parcel shelf that could be mistaken for massive speaker, but in fact helps to ventilate the battery.

Overall: 4.5/5

In answer to the question posed in the intro of this review, I do not truly believe that this vehicle will revolutionise the automotive landscape - but it comes achingly close with its clean-and-green hybrid technology. None of what it Lexus says is complete cow dung - this car is indeed capable of low C02 emissions, while still being exceedingly quick, both in a straight line and through a series of sweeping left-right corners. But at present it's not enough to make the public and other automakers drop everything to read all about it.

But that time is not far off - you can almost smell it.

It's a tantalising proposition this one, and though the price may appear somewhat steep for a Japanese car, it matches it's German rivals in terms of standard features, and in regards to engine performance and fuel efficiency it blows similarly priced models out of the water. Without doubt, this is one of the most remarkable cars I've ever driven. It's quick, it hugs corners with far more gusto that I'd envisioned and is incredibly frugal. Expensive, yes, but well worth the price in my mind.

Priced at $121,990, the GS450h is $15,000 cheaper than the V8-engined GS430 model and $10,000 more than the GS300, and considering the huge array of standard features, it makes for an intriguing luxury selection. 

This is the kind of car that someone like former US vice-president Al Gore would drive. It's the kind of opulent luxury car that will reduce your carbon footprint, allowing you to travel between business seminars in the lap of luxury, while at the same time providing the kind of visceral thrills that have never before been associated with the word 'hybrid'.

There is the old question of cachet value that will certainly rear its head, and what would you rather your peers to see you driving - a V8-powered BMW 5 Series or one of these. Most people would choose the Beemer, but Lexus is making inroads in this regard with its new designs, which give this model and others more road presence with their chiselled looks.

My hat goes off to Lexus - the world's first volume-production rear-wheel drive hybrid car is an incredible engineering feat, and a very practical luxury car to boot. I was expecting many aspects of the GS450h to be imperfect, but in this test I found very little to complain about. It's an intelligently developed luxury vehicle that shows just how effective a hybrid system can be in creating a luxury performance vehicle.