Under current rules, vehicles that meet the emissions standard escape a 3% scale charge levy.
But this will change from January 1, when the waiver ends, meaning drivers will see their tax bills rise from April 6, 2006.
A survey carried out by ALD Automotive on 200 customers found that only 32% of companies have brought forward company car diesel orders.
Deputy managing director Nigel Fletcher said: ‘Some companies clearly have the flexibility within their vehicle replacement policies to bring forward diesel car orders to help their employees escape the tax rise.’
But he added: ‘The imminent increase in benefit-in-kind tax on Euro IV diesel-engined company cars provides fleets with the ideal opportunity to reassess their ongoing commitment to diesel vehicles.
‘The tax rise impacting on diesel models will clearly improve the relative benefit-in-kind position of petrol-engined models. Therefore, fleet operators and company car drivers should recalculate the tax burden before making a decision.’