It’s not long ago that chairmen and women were all swapping into diesels so as not to appear unnecessarily wasteful to their workers.

But Lexus’ new hybrid luxury car will win the green PR battle over its competitors hands down.

Due to arrive in the UK in October, the LS600h – a four-wheel drive petrol/electric version of the firm’s luxury LS saloon – will command a premium of around £13,000 over the current range-topping £71,000 petrol LS460 model, and the cost of its long-wheelbase stablemate is set to top £90,000.

Lexus GB director Steve Settle said: “Pricing has yet to be finalised but substantial interior trim differences and four-wheel drive are likely to make our new flagship at least £13,000 more expensive than the LS460 in SE-L form. But this is a significant entrant in the premium luxury segment and it has no direct competitor.”

Speaking at the launch of the car, Mr Settle revealed that the UK division already has orders for 102 of the 250 examples which will be imported this year, accounting for half of LS sales. He added: “We intend this to be a car that will never stand in the showrooms because we need to keep tight control on supply and demand. But I am pleased that it is attracting a remarkable amount of interest from the chairmen of high-profile companies.

“The good news for us is that 62% of our advance orders are conquests from Mercedes-Benz and BMW, and we’ve even won a customer from Bentley, which was a surprise. This is encouraging and a big move forward for the brand. I see no difficulty in registering 350 units in 2008.”

Mr Settle said Lexus sold 14,700 cars in Britain last year and claimed the brand was tapping into a ‘growing proportion’ of customers who want to be seen to be going green. Of that figure, around half were sold to fleets.

“The point is that they don’t want to give up on using the big cars that they like,” he said.

“We’re finding people are starting to feel uneasy about driving large cars and are turning to the hybrid solution because it allows them to have what they want with the lowest carbon footprint – and that makes them feel better.”

The LS600h combines a 5.0-litre V8 petrol engine with an electric motor to provide a combined 445bhp with average fuel economy nudging a claimed 30mpg and CO2 emissions of 219g/km. In contrast, the LS460 returns 25.4mpg and emits 261g/km of CO2. Although the LS600h sits eight bands lower for benefit-in-kind (thanks to a 3% reduction for hybrids), its much higher list price will make it more expensive in tax terms – not that this should trouble buyers of £90,000 saloons. However, at least it’s exempt from the London congestion charge.

Behind the wheel

This top-drawer Lexus makes environmentally-friendly driving as good as it is likely to get.

Packaged to take on the best in traditional luxury travel from German manufacturers, the LS600h has such a quiet demeanour that it’s hard to tell which power source is driving the wheels in normal driving conditions.

Prod the accelerator and a combination of beefy V8 power and significant extra electric thrust soon has the car surging ahead with a low, muffled growl, but for most of the time progress is as silent as it is swift.

There’s no doubt the technology is both complex and costly, but this is a powertrain that really impresses as speed rises, and our test on derestricted German motorways suggests the Lexus might be the quietest car around when cruising at 100mph because the engine is lazing along at a mere 2,000rpm.

Weighing 2.3 tonnes, this saloon is heavier than a Mercedes-Benz S-Class as well as roomier, so it is better suited to major highways than byways. Having said that, sophisticated multilink and air suspension allow surprisingly agile progress over cross-country routes.

Rear seat space in the long-wheelbase version is even more generous because the extra 120mm of length has been dedicated to increased legroom. Passengers get a ‘comfort seat’ with a multi-programme relaxation system incorporating a massage function and heated and chilled seats, and climate control featuring a body temperature sensor that can more accurately assess the ambient temperature in the cabin and adjust the temperature to suit.

Ultimately, the LS600h doesn’t have the slick handling of the Audi A8 – one of its benchmark rivals – because the ride is softer in the normal ‘comfort’ setting, but firmer control is available in the Lexus via a switch that offers a choice of damping.

Fact file

Model: LS600h
Max power (bhp/rpm): 445/6,400
Max torque (lb-ft/rpm): 383/4,000
Max speed (mph): 155 (limited)
Fuel consumption (mpg): 29.7
CO2 emissions (g/km): 219
On sale: October
Price (est): £84,000-£90,000