By JOSHUA DOWLING
JOSHUA DOWLING tests a new kind of performance luxury car against the benchmark of the class.
Lexus has released the world's first petrol-electric luxury car. But if you can afford a $120,000 sedan, presumably you can afford the fuel, even if it does cost $1.45 a litre.
So why does such a vehicle exist and will buyers greet it with the same enthusiasm as they did Toyota's petrol-electric Prius, the world's biggest-selling hybrid car?
Toyota's luxury division, Lexus, says the GS450h is not necessarily about fuel economy, it's about performance, too.
While the Prius mates a frugal 1.5-litre, four-cylinder engine to an electric motor, the Lexus combines a 3.5-litre V6 with electric power. Given that electric motors have instant torque, car companies have discovered that the fuel-saving technology can also be used to improve acceleration.
Lexus claims its new hybrid-powered mid-sized luxury sedan can complete the 0 to 100kmh sprint in a supercar-like 5.2 seconds. It's the fastest Lexus ever built and that is why we found ourselves this week visiting the high temple of Australian horsepower, Mount Panorama, home to the iconic Bathurst 1000 motor race.
There are no Holdens and Fords roaring around the race track today, only those driven by tradies and tourists on this public road. But we do have an interesting proposition for the Lexus: the benchmark for performance luxury sedans, the Mercedes-Benz E55 AMG. The E55 is the world's fastest sedan. Official claims put the 0 to 100kmh sprint at 4.9 seconds. While the E-Class is crammed with safety technology, in this company its drivetrain could be accused of being old-tech. It has a whopping 5.4-litre V8, with a supercharger bolted to the top of it to help low-end pulling power. In short, it's a weapon and will happily dust a Porsche as easy as brushing your teeth. And, best of all, it'll do it with all the comforts you'd expect of a Mercedes sedan.
Given that luxury cars are not all about straight-line stamina, we decided to drive the pair from Sydney to Bathurst, to get a mix of city driving, the bumpy back roads of the inner-west and the rise and fall of the Blue Mountains, before the long, flat run into Bathurst.
It would prove to be a good test of both cars in conditions that don't necessarily suit them. For example, hybrid cars are at their best around town, as the petrol engine shuts down and the electric motor activates in stop-start traffic to cut fuel consumption. Hybrid cars are also supposed to be at a disadvantage on the open road, as they rely on the petrol engine most of the time, particularly up hills and on long straights, and miss out on the occasional free kick from the electric engine.
It's the opposite for the Mercedes. The big V8 still has to idle while sitting at the lights and if you're tempted to take advantage of its acceleration, it'll quickly develop a thirst for fuel. On the open road, however, the engine's massive torque (a truck-like 700Nm) helps the Mercedes tick along with remarkable frugality.
Executives from both Mercedes and Lexus were nervous about this comparison. And fair enough, too. These two cars couldn't be more different. The Lexus hums as it comes to a halt, or moves away from rest, running quietly on its electric motor until it gets up enough steam to warrant use of the petrol engine. The Mercedes snorts, grunts and sounds like there's a sawmill under the bonnet, ready to shred anything and everything before it.
Lexus wasn't sure the GS would be a match for the Mercedes in terms of performance and Mercedes has never pitched the E55 as an expert on economics. So the results are likely to surprise them as much as they surprised us.
In Sydney traffic, just as the morning peak is fading and the roads become less clogged, the digital fuel consumption gauge in the Lexus is showing an average of about 10 litres/100km, the Mercedes averages between 12 and 14 litres/100km. Neither car has anything to crow about. While the Lexus figure is good for a car of this size and weight, a fleet-pack Holden Commodore V6 in the same circumstances is likely to consume between 10 and 12 litres/100km.
A Corolla would drink about 8 to 10 and a Prius would sip fuel at a rate of about
5 litres/100km.
On the run up the Great Dividing Range, between Penrith and Lawson, the fuel consumption readouts on both cars are about the same as they were in the city. Even though the engines are working harder as the Great Western Highway winds and climbs, the cars are spending less time in stop-start traffic as we get a surprisingly good run over the mountains. The torque of the Mercedes V8 and the torque provided by the GS450h's electric motor (which cuts in and out seamlessly) help keep consumption down.
On the downhill run to Lithgow, the Lexus V6 engine spends most of its time dormant and the readout on the dash shows that with every application of the brakes, the electric motor's battery stacks are being recharged. Instant consumption drops to zero on the Lexus and the average starts to drop to 8 litres/100km. But the downhill run does the Mercedes some good, too. As with many modern cars, the engines consume little fuel on long downhill sections. While the E55's instant consumption readout varies from 2 to 6 litres/100km, it brings the Mercedes's average down to 10.5 litres/100km.
On the long, flat run between Lithgow and Bathurst, where we coast along close to 100kmh, the fuel consumption readout on the Lexus increases slightly to between 8.5 to 9 litres/100km and the Mercedes settles to about 11 litres/100km. Had we driven the Mercedes more enthusiastically, this figure could easily have doubled. Nevertheless, the Mercedes figure we recorded is surprisingly good given the power that lurks within.
(If the E55's five-speed auto helps open-road economy, we can't wait to see how much of an improvement the new seven-speed auto will bring to the E55's replacement - the 6.2-litre V8-powered E63 - due on sale late this year.)
In short, we were expecting better performance and fuel economy from the Lexus and the Mercedes to drink more than it did.
Time to test the acceleration claims. On flat tarmac, the best we could extract from the GS450h was a 0 to 100kmh time of 6.9 seconds. We then tried a couple of downhill runs, to see what the GS is capable of in a best-case scenario and both times the clock stopped at 6.1 seconds, a far cry from the Lexus claims. The Mercedes, meanwhile, recorded 5.1 and 5.2 second times with monotonous regularity.
That said, the GS450h's acceleration is deceiving, especially given the smoothness of the constant velocity automatic transmission. Its quiet and refined engine can barely be heard from the comfort of the plush cabin. The GS450h's biggest strength is its overtaking power, where there is little delay from the time it takes to squeeze the throttle and feel it surge forward. The Lexus accelerates with a high-tech whir, the Mercedes accelerates with the roar of a heavy metal rock band.
As the sun sets at Bathurst and we prepare for the run home, I'm more confused about the Lexus than I was before we set off from Sydney.
Lexus says the GS450h provides "guilt-free high-performance", that is, you're getting a quick car while not burning as many fossil fuels as other vehicles of similar size, weight and performance. Indeed, the GS450h out-performs the bigger-engined and more expensive GS430 in both acceleration and top speed. And it uses less fuel in the process. But I'm not sure about the company's perfomance claims.
Lexus is also committed to expanding its range of hybrid cars. A hybrid version of its flagship LS limousine is due in Australia early next year and a hybrid version of the Lexus RX soft-roader is due in local showrooms by the end of this year. The company believes that petrol-electric hybrids are a cleaner alternative to diesel power and a more environmentally friendly way to deliver performance.
But our initial question remains: if you can afford a luxury car, surely you can afford the fuel? "It's a conscience clearer," says Lexus spokesman Mike Breen. "It's not all about fuel economy, it's about getting the most from finite resources."
PRIUS V LEXUS
They're both petrol-electric cars but they have different levels of fuel efficiency. In real-world driving conditions, the Prius sips between 4.5 and 5.5 litres/100km of petrol and some owners have reported travelling up to 900km on one tank. The Lexus GS450h, meanwhile, recorded between 8.5 and 9.5 litres/100km on our test. The Prius has a 1.5-litre, four-cylinder engine mated to an electric motor while the Lexus has a 3.5-litre V6 mated to an electric motor. Lexus is not sure what demand will be like for the GS450h but at $121,990 it is priced between the GS300 ($95,200) and the V8 GS430 ($137,200). The Prius has sold beyond expectations here and overseas. Priced from $37,000 there is a three-month waiting list locally and sales are up 21 per cent this year.
THE CARS LEXUS GS450H MERCEDES-BENZ E55 AMG Price $121,900 $225,600 Engine 3.5-litre V6 (218kW) 5.4-litre V8 (350kW) 650V electric motor (147kW) Supercharged Transmission Constant velocity Five-speed automatic automatic Weight 1900kg 1835kg Fuel economy rating label 7.9 litres/100km 13.1 litres/100km Actual consumption on test 9 litres/100km 11 litres/100km Claimed 0 to 100kmh 5.2 seconds 4.9 seconds Actual 0 to 100kmh 6.9 seconds 5.1 seconds Warranty Four years/100,000km Three years/unlimited km