Data from mileage capture company The Miles Consultancy shows that the most efficiently-driven Prius achieved 68mpg (10% better than the official figure of the second-generation model) while the worst was 46mpg (34% worse than the official mpg).

Robson concedes that hybrids “fit the test well”, but he says: “Hybrids are no different to a standard diesel or petrol.

If you put your right foot to the floor you’re not going to get the best fuel economy.”

Peugeot doesn’t offer driver training as a matter of course, but it is an option for dissatisfied customers. It also offers online tutorials.

Similarly, Vauxhall provides a DVD for the Ampera which explains driving techniques.

Case studies

Peter Bonney, fleet manager, Salvation Army

More than 10% of the Salvation Army’s 730 company cars are hybrids.

Fleet controller Peter Bonney admits take-up isn’t due to a conscious decision from the Salvation Army.

“I’d like to claim a clever strategy or green initiative, but the truth is we’ve simply made some hybrids available and drivers have been attracted by the personal financial benefits,” he says.

“We don’t make a saving in contract hire rentals as hybrids tend to be more expensive than our benchmark car.

"We do factor in the employer’s Class 1 NIC costs and drivers then have to make up any cost over the benchmark by way of personal contribution.”

The majority of the 88 hybrids are Honda (the Insight and Jazz) although recently drivers have also been opting for the Toyota Auris.

The Auris and latest version of the Insight qualify for the London Congestion Charge discount, but Bonney says that isn’t the main reason hybrids are being chosen.

The Salvation Army’s decision to move away from diesels in 2010, due to diesel particulate filter problems and the fact that most journeys are urban-based, have also spurred drivers to choose hybrids.

Bonney points out: “They are ideal for driving round town. I’ve got an Auris and I spend most of my time crawling round in London traffic, running on electric.”

Economy has proved to be “almost diesel-like”, although he admits the figures for the fleet are still around 10mpg lower than the official combined figure.

He is currently averaging 55mpg, although has achieved 60mpg on longer journeys.

Some of the vehicles have been on the fleet three years and there have been no reliability or downtime issues.

The only downside, according to Bonney, is that a hybrid can’t tow so they can’t be used with a small trailer or caravan.

“There are lots of upsides to hybrids,” he adds. “I’m a great fan.”