James McGeehan, of 47 Ballyraine, was stopped by customs officers in Letterkenny on December 11th, 2009.
When officers dipped his car using the normal markers they found it showed a green colour which identified the fuel being used was illegal.
Customs officers told Judge Paul Kelly that when asked if he understood that he would be facing a fine McGeehan replied “I’m as poor as piss with no money.”
State solicitor Ciaran Liddy told the court that the relevant samples had been sent off for analysis and had proven to be green diesel.
The court also heard there had been a previous conviction of a similar nature in September last year for which he was fined €2,500.
Judge Paul Kelly fined McGeehan €2,500 and took a second charge into consideration.