He said the price differential in Wanganui always prompted comment from customers who called into his service station.
Dave Bodger, Gull NZ general manager, had told the Chronicle earlier this year that his company was able to keep its prices down because it imported through a single terminal at Tauranga and sourced its fuels from the Asia-Pacific basin rather than the Marsden Point refinery.
An AA spokesman said the price drop was mostly due to further reductions in commodity prices and a slight strengthening of the NZ dollar which is back over US67c for the first time in a month.
"Oil prices have fallen to US$40 a barrel which is nearly the lowest since January 2009," he said.
The last time refined fuel commodity prices were this low, petrol prices were $1.73 a litre and diesel $1.07 a litre.