FUEL and car policies need to be worked out separately, said Alison Chapman, lead tax partner of the Deloitte automotive sector group.

She told delegates to start with a blank piece of paper and be sensitive to how the business environment is changing.

She said: ‘You may want to tweak your fleet to look green, by encouraging staff to use lower-carbon cars, and can often do that without spending too much money.’

There was a contrast between company and driver aims. Employers wanted to control costs, risk, image and balance, while keeping staff content.

Employees wanted value for money, lifestyle choice and freedom from risk.

Chapman said: ‘Keep making savings, and hope all the people who are affected don’t object.’

Adam Trevaskus, head at Lloyds TSB autolease cash for car specialist Whitechapel, said retaining the best people was getting harder, and one way was to allow car ownership to complement company-owned vehicles.

Key criteria included the level of annual business mileage (7,000-plus) and staff turnover (no more than 30% a year). ‘If a driver leaves, you must know who is going to pay any settlement,’ said Trevaskus.

The conference heard LPG prices should remain at least half of those of fossil fuels for the next three years, with greater savings for fleets refuelling from their own supplies, said Nigel Underdown, head of advice at TransportEnergy’s Energy Saving Trust.

By contrast, diesel cars with common rail engines were becoming more expensive, raising the annual mileage needed to make enough fuel economy swings compared to petrol cars to make them cost effective.

Final submissions to the latest DfT consultation on how to encourage the cleanest and lowest-carbon vehicles was due by the end of this month. This would determine when the sale of alternative fuel vehicles would be sustainable.

Eric Westlake, Vauxhall Motors’ LPG sales manager, said UK drivers were loath to change fuel, and took 10 to 15 years to start the diesel boom. LPG accounted for 1% of vehicle sales and was unlikely to increase its share but Westlake described it as ‘the stepping stone to fuel cells’.

Rob Anderson, a senior fleet adviser to the DfT TransportEnergy best practice programme, said selecting the right vehicle, with whatever fuel source, was essential for fleets, otherwise, he said: ‘What follows is an exercise in damage limitation.’