Lorry driver Rod Quaite lives in Broughshane near Ballymena in County Antrim.
He told BBC News NI he had noticed differences in the size of the price increases during his journeys for work.
“The further down towards Enniskillen you go, the dearer it’s getting – the cheapest I saw was £1.64,” he said.
“What I can’t understand is why diesel’s been hammered so much and petrol isn’t.
“Yes, petrol’s gone up a bit, but it’s gone up nowhere near as much as diesel.
“It’ll not be long until it’s hitting £2 a litre.”
Despite the rises he said he had not changed his driving habits.
“I don’t drive very much out of work, I get enough driving at work, but I like to keep the tank full for emergencies,” he said.
“I’m not the best paid person in the world, but I’m in the position where I can afford it.
“Long-term, I don’t know.”