The Eco-friendly Lexus GS 450h

Toyota and its upmarket Lexus brand need an additional joint venture partner in the field of audio systems. I suggest Mr Whippy.

Even the dogs slobbering happily along with their owners in the middle of crowded Fore Street, the 9ft wide thoroughfare with delusions of grandeur that serves as the high street of Salcombe, Devon’s yachtie haven, seem unaware of the nearly 2 tonnes of potential nemesis creeping up on them.

It is hard to resist wafting silently up behind pedestrians in a petrol-electric hybrid, running in battery mode, to see who jumps back with “Ywthdtcf” syndrome. (Not “Ywthdtcf” as in some remote Welsh village, but as in “Yikes! Where the hell did that come from?”) A built-in ice-cream van chime would, of course, put a stop to my juvenile behaviour. But if battery-powered cars are to become widespread, this issue of audible warnings will have to be addressed more seriously.

Such opportunities for slightly risky silliness have, admittedly, become rarer as Toyota’s pious Prius has caught on. (Toyota has now sold well over one million of its hybrid globally.) But a thumping great executive hybrid like the silent stalker of Salcombe – more than £47,000 worth of Lexus GS 450h – is still an extreme rarity and therefore another matter altogether.

It is a car of many virtues in addition to its rarity (and hence, of course, its perceived exclusivity). Not the least of these is that, as a hybrid, the GS 450h is exempt from London’s £8 daily congestion charge and is likely to be similarly exempt in other cities that follow London’s example. The 450h is also exceptionally economical for a luxury conveyance that accommodates five in spacious, leather-lined comfort. I averaged 40 miles per gallon over more than 800 miles of driving, without undue self-restraint.

But it is debatable whether such upmarket hybrids – and there are plenty more to come, including one from Porsche – truly merit that congestion charge exemption. The 450h emits 179 grammes of carbon dioxide per kilometre: that’s very good by conventional large executive car standards, but it’s also hugely more than the 104g/km of the Prius, and more than a basic diesel version of the similarly sized Mercedes-Benz E-Class saloon.

The rationale, of course, is pour encourager les autres – to help persuade all carmakers to intensify their efforts to produce more environmentally friendly cars. (With the exception of CO2, victory is close in the technological battle against most exhaust pollutants.)

Potential buyers need not get excited, however, about April’s much-heralded government announcement of up to £5,000 in subsidy for anyone who buys an all-electric or hybrid car – the 450h, like every other current hybrid, does not use “plug-in” technology and would not therefore be eligible for the sweetener.

For the first 40-50 miles of a journey, “plug-in” hybrids will run exclusively on their mainly lithium-ion battery packs, recharged overnight from the mains. On longer journeys they will then use a small petrol or diesel engine running at constant speed to charge the battery pack as they go, thereby increasing their range to something approaching that of a conventional car. But no such cars are expected to be on sale from any significant manufacturer until 2011, making the whole exercise look rather like political spin.

The 450h, like the humbler Prius and Honda’s new Insight, recharges its battery pack solely from its engine (in this case a lusty, 4.5 litre, 292 horsepower petrol unit) and from storing the energy used under braking, giving it the ability to cruise around town silently and without pollution. On the open road, where much more power is needed, both electric motor and petrol engine spend most of their time powering the car simultaneously.

Since the electric motor adds considerable horsepower and its maximum torque can be tapped from the second that it comes into play, the result is very lively performance indeed. The 450h is a genuinely fast and quite spectacularly refined car, with spirited handling and the capability to cover very long distances without leaving its occupants fatigued. As you would also expect of Toyota-group cars manufactured wholly in Japan, build quality is more than a match even for its most prestigious European rivals.

All that notwithstanding, you might expect that a plan I hatched to take the Lexus into the very heart of greenness in the UK – Cornwall’s vast Eden Project – for a “photo opportunity” would have been vetoed as pro-car propaganda by those responsible for the giant plant-filled biospheres. Not so. The attitude of Gus Grand, the project’s climate change programme manager, and her colleagues is seen by motor industry executives as a breath of – no, really – fresh air in a debate about the car’s contribution to global warming that has become increasingly strident and emotional.

Were it not for the crisis in the motor industry induced by recession, the Eden centre would by now be in the final stages of setting up another of the “Sexy Green Car” exhibitions it has staged in the past few years. “General Motors and Ford were fantastically supportive last year,” Grand recalls. The Eden Project’s rationale for staging its own motor shows of hybrid, battery-powered and economical diesel cars is straightforward. The £130m project, sited in remote Cornish countryside, is the county’s second-largest employer, with 500 staff. It tried initially to ship its employees in using various public transport schemes, but these were too complex and time-consuming to be properly workable.

“The reality is that lots of people want and need their cars to get here,” says Grand. “It just doesn’t work to try and force them into doing something else. Instead, they need persuading that ‘green’ cars are an attractive proposition in their own right