Would someone buying a big, powerful car also be concerned about its exhaust emissions? It may sound curious to some, but that is apparently the buyer profile of those who have booked a Lexus LS600h L luxury limousine.

As a petrol-electric hybrid, this flagship Lexus model is more environmentally friendly than usual but it bucks the trend by refusing to pretend that it is a fuel-sipping econo-car. No, the world's first V8 hybrid model with all-wheel-drive also happens to be the most powerful on the market.

Its five-litre engine works with two electric motors and a battery to churn out a combined output of 439 hp.

At first glance, the LS600h L looks a lot like a conventional long-wheelbase LS460. It has a five or four-seat configuration, with the latter boasting extra premium features like an Ottoman seat with built-in massager and an infrared body temperature sensor to maintain the desired rear seat temperature.

But apart from blue Lexus badges and bigger 19-inch wheels, there are also a few basic differences. For example, the LS600h L has a larger V8 engine (5.0litres versus the LS460's 4.6) and all-wheel-drive (versus rear-wheel-drive).

There is also an extremely smooth, continuously variable transmission (instead of an eight-speed automatic gearbox) as part of the integrated hybrid assembly.

The addition of the Lexus Hybrid Drive unit also makes it heavier (2,410 kg)than the 2,065 kg LS460 LWB - a weight difference of two somewhat small sumo wrestlers. As expected, the two cars have varying acceleration figures. Zero to100 kmh for the hybrid is 6.3 seconds, against 5.7 seconds for the LS460.

But the advantages of the LS600h become clearer when the fuel consumption figure is compared with the conventional Lexus - 10.8 km per litre under a combined highway/city cycle versus 9.0 - plus the 20 per cent lower carbon dioxide emissions. In fact, Lexus says it has the performance of a six-litreV12 engine but the fuel economy of a three-litre V6.

Despite its more frugal nature, the LS600h L has more torque than a tractor, thanks to the boost from the electric motor. It literally flies off from a stationary start and handles more confidently than the rear-wheel-driven LS460 because of its four-wheel-drive. Depending on driving conditions, the torque to the front and rear axles can be split 30/70 under hard acceleration, 40/60 for normal cruising, and 50/50 on slippery surfaces. It allows the massive sedan to display surprising agility, making it as fun to drive as some of the German competition.

While the LS460 is an amazingly luxurious car with dazzling engineering, it can also come across as strangely soulless. It does everything well but lacks character. The funny thing is, this is not a problem for the LS600h L. It appeals with a unique combination of ample power, all-wheel-drive handling, quiet performance and eco-friendly attributes. It is truly an intriguing proposition, one that no doubt persuaded the 15 people who have ordered it so far.

Engine: 4,949cc V8
Gearbox: 8-step E-CVT Hybrid transmission
Max power: 389 hp @ 6,400 rpm
Max combined system output: 438 hp
Max torque: 520 Nm @ 4,000 rpm
0-100 kmh: 6.3 secs
Top speed: 226 kmh
Price: from $366,139 (with COE and green rebate)
Distributor: Borneo Motors. Tel: 6475-1288