Ian Preece, assistant managing director of Safeguard, Sodexho's environmental services division, carried out the first full commercial trial of the Prius by a major private company in the UK and has volunteered to change his Lexus IS200.
During his three-month trial in the Prius, covering motorway miles as well as urban driving, and making no attempt to optimise fuel consumption, Preece averaged 54mpg, and believes that covering 18,000 miles a year would result in a saving of £1,000 in fuel over his own car.
The Prius qualifies for VED at £105 rather than £155 for conventional petrol cars, and a 40% taxpayer's monthly benefit-in-kind tax bill will be £60 because of discounts for hybrid vehicles.
Preece said: 'How can I justify to my family paying an unnecessary £1,500 in income tax per year just to have a polluting car.'
Jon Pollock, general manager of Toyota Fleet, said: 'We have great confidence in our claims for the Toyota Prius, but it is very gratifying to see them corroborated in this way by such a significant independent source.'