The price of diesel has fallen below $1 per litre.
Gull stations are selling diesel between 96 - 99 cents per litre, the same price as 18 months ago.
However Gull says it has raised the retail price of petrol as a result of higher prices for refined fuel.
BP, Mobil, Caltex and Shell raised the price of 91 octane by five cents to $1.37.9 per litre on Wednesday.
