Rising oil prices are reinforcing the attraction of low-consumption cars. Luckily, Alan Salter finds that eco-friendly no longer means small and slow…

The winds of climate change are blowing through the motor industry – and the car hire fleets are tagging on behind. For years, the “big beasts” who gathered at the Motor Show every summer would be boasting of power and speed as they took to the exhibition stands, yet this time all talk was of mpg and emissions.

Ford’s superb new Mondeo now comes as an ECOnetic variant, offering a combined mpg of 53.3 from its 1.8 diesel engine. Vauxhall’s Vectra replacement, the Insignia, will start from behind when it hits the road in December – its most economical engine is a 2-litre diesel offering just 48.7 mpg.

The prime minister popped in, speaking of “huge opportunities” for a green revolution. Road transport, he said, had reached a “historic turning point”. He could equally have said that the motor industry is drinking in the last chance saloon, with the manufacturers hurrying to finish their pints of strong lager before moving on to the juice bar down the road.

There was an air of panic at the Excel exhibition centre as makers hurriedly tried to convince the world that they are doing all they can to save it. The buying public is puzzled. A survey by the Energy Saving Trust recently found that three-quarters of Britain’s drivers haven’t a clue what their cars’ emissions are.

Hirers, however, are savvier – at least according to the British Vehicle Rental and Leasing Association. It says that CO2 emissions from its members’ vehicles have fallen by three million tonnes over the last four years. John Lewis, the association’s director general, added: “Our members and their customers are doing more than just choosing lower-polluting cars. They’re covering fewer miles. Average mileages have reduced from more than 25,000 miles per year to 21,643 miles last year.”

Figures from National Car Rental, part of Europcar UK Group, suggest business drivers are planning road travel more carefully. Although overall the average miles per rental have fallen, National has seen increases in the mileage incurred in larger vehicles such as estates and people carriers.

“While the majority of rentals are in our small and medium-sized vehicles, this increase in the mileages incurred in larger vehicles indicates people are choosing more spacious cars for longer journeys, with opportunities for sharing the driving and cutting costs,” said Tim Bailey, fleet director.

Along with its sister companies Enterprise and Alamo, National claims the world’s largest fleet of fuel-efficient vehicles, with more than 440,000 vehicles which average at least 28 mpg and more than 237,000 averaging 32 mpg or better.

Rental firms detect a growing interest in both emissions and fuel consumption, and are increasingly catering for hirers with a green conscience, but who don’t want to arrive for their meeting in a G-Wiz. Hertz’s “Green Collection” offers a CO2 output level of less than 140g/km and achieves 40-65 mpg, depending upon vehicle size.

I have to say that they are doing themselves a disservice. I borrowed a Volkswagen Passat Bluemotion – heavily promoted by Hertz – to drive from Manchester to the motor show and back. My outward journey on the M6 returned a figure just inside the Hertz band – 64.5 mpg. But on the way back via the M1, consumption was an astonishing 67.4 mpg.

And this was no economy drive at 50mph in the slow lane. I was driving at the national speed limit in a medium-sized saloon of passable luxury, avoiding where possible heavy acceleration or braking. The various methods of calculation are confusing but I have a suspicion that my carbon footprint on that particular journey was less than if I had taken the train.

Avis, parent company of Budget, with 18,500 cars in the UK and a 120,000-strong European fleet, offset its emissions last year in conjunction with The Carbon Neutral Company. A spokesman said: “We seek to minimise emissions from our fleet by introducing more environmentally friendly vehicles in more locations.”

In this country, that means that film-star’s favourite, the Toyota Prius. There are also Ford flexi-fuel cars in France; LPG-fuelled Volkswagens in Italy; BMW 1 Series with stop-start technology in Spain; and Honda Civic hybrids in Germany and Portugal. “We have begun to provide several major clients with data, which allows them to quantify easily their carbon emissions from Avis rentals. We will work with such clients to reduce their carbon footprint in future years,” the company says.

“We are also helping individual customers to reduce their environmental impact. Our redesigned website makes it easier for them to make their journey carbon-neutral when they book online. For the second year running, the number of customers using this service has risen by over 20 per cent and continues to increase.”

Toyota’s “hybrid” technology – the combination of an electric motor and a petrol engine – first captured the world’s imagination with the Prius. And, although I remember getting a miserable 38 mpg from a first run on its UK launch three years ago, I quickly realised that zooming about on motorways and country roads is not what the technology is about. The economy comes from the use of the electric motor below a certain speed. So at 60 or 70 mph, it’s just a normal car.

I have seen David Cameron arrive at an engagement in a Prius but his famously preferred hybrid, of course, is the GS 450h from sister company Lexus. (The choice was rather tainted when it was revealed that it was used to carry the Conservative leader’s brief case and shoes while he cycled to work for the photographers.)

Lexus has, in fact, just about cornered the top end of the hybrid market. The company also boasts the RX 400h – the world’s first high-performance hybrid SUV – and the LS 600h luxury saloon. If you are senior enough, there are several companies which will rent you a Lexus and a chauffeur to go with it.

So which rental car do you choose? Paul Clarke of Green-Car-Guide.com said: “It really does depend on what kind of journey you are making. You can’t beat a hybrid like the Lexus for driving around town, but for long motorway journeys, you can’t really do any better than a BMW 5 series diesel.”

budget.co.uk, hertz.co.uk, avis.co.uk, alamo.co.uk, europcar.co.uk, nationalcar.co.uk

Top ten fuel-saving tips

1. Walk! Journeys of less than two miles cause the most pollution and are inefficient in terms of fuel consumption.

2. Plan your route. Take the most direct route and go off-peak if possible.

3. Hire a car from a company which services it regularly. Inefficient, under-serviced engines can reduce fuel economy by 10 per cent or more.

4. Check your tyres. Correct tyre pressures will keep wear down and fuel economy up.

5. Obey the speed limits. Doing 56 mph uses 25 per cent less fuel than 70 mph and a smoother driving style can bring significant fuel-saving. But never coast to save fuel – it is dangerous.

6. Reduce the drag factor by removing roof racks and carriers when not in use. Driving with the window open also increases drag and lowers fuel economy. Remove unnecessary boot luggage. Air-conditioning lowers fuel economy so use the vent settings as much as possible instead.

7 If you get stuck in traffic, switch off the engine. Green BMWs do it automatically.

8 Plan ahead and gently let the speed of the vehicle bring you to a halt as you join a queue.

9 Reverse in when you park. When you start off again, the engine will be cold and at its most fuel inefficient. Save £2 a week by driving smoothly away without having to reverse when the engine is cold.

10 Don’t fill the tank up to the very brim. That extra weight will itself reduce fuel efficiency.

From the Institute of Advanced Motorists