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2007 Lexus GS 450h – Seduced By The "Electric Turbocharger"

We all know that until gas prices go up to somewhere over $4.50/gallon and stay there for a goodly bit of time, the wonder of gasoline/electric hybrid technology won’t deliver enough in fuel savings to pay off the incremental cost of most systems for the average driver. So the reasons for hybrid interest lie somewhere beyond economy. Honda, purveyors of the Civic Hybrid and the amusing but impractical Insight, decided that the concept of a performance hybrid might have some traction. The company teased us with the concept of a performance-based hybrid in the guise of the Accord Hybrid. But for several reasons, not the least of which was the combo of less-than-earth-shaking acceleration with a $30,000+ price tag, the anodyne hot-rod hybrid Honda has failed to perform in the market. In the case of America’s most popular hybrid vehicle, Toyota’s Prius, the obvious reason for its success and buzz is the car’s distinctive styling that makes the petit five-door hatchback stand out for the crowd. It all but screams “I’m making a statement.” And in the case of the Prius that statement is one of saving the environment.
Beyond the Prius and Insight, hybrids are far less distinctive on the road. Pretty much all that differs the majority of hybrids from their conventionally propelled sister vehicles are wheels, badging and, in one or two cases, a specific grille.


Invisible Lexus GS 450h Tests Consumer Demand for Distinctive Hybrid Styling
So it is with the latest addition to the Toyota/Lexus lineup of Hybrids. Beyond a set of chrome-trimmed 18-inch wheels, a small “h” on the rear and an even smaller Hybrid badge in its lower-body moldings, the 2007 Lexus GS 450h could pass for the V8-powered GS 430.
Jim Hall, AutoPacific Vice President and VehicleVoice contributor had a recent opportunity to drive a GS 450h during one of his frequent trips to the mother ship in California. Impressed, he coined the term “electric turbocharger” to describe the impact of the Hybrid Synergy Drive on the performance of the GS.


Hybrid Joins Powerful V6 to Give V8+ Power

In place of the 430’s 300HP 4.3L bent eight, the hybrid mounts a 292HP 3.5 V6. All swathed in plastic close-out panels with a brilliant orange set of electric cables readily visible adjacent to a silver shroud emblazoned with words Hybrid Synergy Drive that almost completely conceals the engine, the under hood has the feeling of something you’re not actually supposed to be looking at let alone be messing with. It’s almost like the only thing missing is one of those “No Consumer Serviceable Components Inside” labels on the back of a home stereo tuner. But the power doesn’t stop there. The hybrid system uses a 288-volt nickel metal hydride battery pack installed behind the rear seat. The battery’s power is directed through a boost converter that raises voltage to a maximum 650V DC. An inverter changes this to AC.
MG1 and MG2 are the Electric Turbocharger
Rather than fit a conventional automatic transmission, the GS 450h utilizes an advanced two-stage motor torque multiplication device for its electronic continuously variable transmission (ECVT) motor. It’s really a big motor assembly but you can think of it as a virtual transmission. The first motor-generator (MG1) can generate a peak of 180HP while the second unit (MG2) has a maximum output of 197HP. The second motor also operates at peak speeds of 14,400 rpm! Each has specific functions and does double duty to operate as both the motors and generators, although MG1 is used as a starter motor and provides no motive force (Hmm, a 180HP starter, the mind boggles). The engine-driven generator (MG1) can also charge the battery pack or provide additional power to MG2 as needed. Because of the way the system works, the peak output of the gasoline engine and motor-generator sets is 339HP. While this would be considered impressive for a 3.5L normally aspirated V6, it is only part of the story.
Under acceleration MG2 is used to get the car underway and can continue to do so on its own up until about 28mph or unless the system determines additional power is required. Then the V6 engine starts up and things begin to happen quickly. Toyota claims a 0-60mph time of 5.2 seconds but some enthusiast magazines have seen a sub 5-second time or two. During braking, the electric motor is operated as a generator, converting the kinetic energy of the moving vehicle to electrical energy that’s uses to keep the nickel metal hydride batteries topped off. While the GS Hybrid is quite impressive off-the-line, transient acceleration is where the car really shines. 30-50MPH is a snap at a a bit more than two and a half seconds. The freeway merging 50-70 number comes up in a sports car-baiting 7.8 seconds. Mighty impressive for a 4100 pound sedan.

Which brings up one of the issues with the GS hybrid, its heft. Compared to the V8 GS which has a manufacturer’s declared curb weight of 3,748lbs, the V6 hybrid tips the scales at 4,134lbs. Compared to the base 3.0L V6 GS curb of 3,536lbs, the Hybrid looks to be absolutely portly. The majority of this difference is the battery pack and related structural changes.
Intoxicating Driver
Still in spite of its not-insignificant avoirdupois, the GS is an intoxicating car to drive. The oomph the car has off the line is astonishing, performing as though it’s equipped with a electric turbocharger. The car’s motor-generator system is smooth as a politician’s town meeting speech at delivering power. With no conventional gears and a more torque than a six-pack of Honda Fits, the GS 450 h’s “virtually CVT” exhibits none of the stretchiness or so-called “motor-boating” of most continuously variable transmissions on the market.
The Result is a GS Priced Just Under $60K
With a base price just five bucks shy of $55,600, the premium for a the hybrid technology works out to $3,525 over a V8 GS. The GS 450h has a few extra features as part of its standard kit that are either unavailable or optional on the other GS models. These include a rear parking camera, electric sunshade and a cool energy management display in the center stack. But when all is said and done this stuff doesn’t account for much more than $750. So for an extra $2,500 or so you get performance that’ll leave the V8 GS in the dust. The hybrid should also leave the eight-cylinder model at the gas pump. And although even with gas prices where they are today, the typical customer won’t be able to pay off the price premium demanded by the hybrid drive system in the average ownership period, the fuel economy figures for the GS 450h are impressive. To put its mileage in perspective, the EPA fuel economy numbers for the GS 430 are 18mpg city and 25mpg highway. By comparison the Hybrid turns in 25mph and 28mpg numbers respectively.

Among the few things you don’t get with the GS 450h is a tachometer. In place of the tach there is a cryptically labeled “Power” gauge that reads from 0 to 250 kW. For the less metrically minded of you, that works out to 335.3HP or darned close to the GS Hybrid’s listed 339HP peak system power. Another thing the price differential doesn’t get you is distinction. Other than the aforementioned wheels and badging, the is nothing to distinguish the GS from it’s lowly brethren. A more distinctive grille, different front and rear fasciae and a set of tastier, 19- or maybe even 20-inch wheels are called for.
Other than that, this is one sweet automobile. And a heck of a way to save the environment… QUICKLY.

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