The Energy Saving Trust (EST) is providing the funds for fleets wanting to reduce vehicle emissions in a separate programme to the one run in England.
Phil Sellwood, chief executive at the EST, said: 'CleanUp grants exist to help support diesel vehicle operators in cleaning up their fleet in a manner which is both effective and affordable.
The new fixed grant system that came into effect on April 1 is not only more transparent, making it clear from the outset what grant applicants will receive, but also easier to apply for.
'These changes have been made to ensure that the new system can continue to provide real cost and environmental benefits to the customer.'
The EST announced last month that for England's CleanUP programme, it would receive Government funding of £26 million for the 2004/2005 financial year, a freeze on last year's budget.