Supermarkets are cutting fuel prices amid a fall in wholesale costs.
Morrisons on the town's West Langlands Street will slash both petrol and diesel prices by up to 3p per litre.
Asda on Queen's Drive will also drop the price of diesel, with petrol prices falling by 1p.
The announcements follow a recent drop in wholesale costs, with the price of oil falling by around nine per cent last month.
Four consecutive months of average fuel price increases in the UK mean that, since February, the cost of filling a typical 55-litre family car has increased by £6 for petrol models and £3.80 for diesel vehicles.
AA fuel price spokesman Luke Bosdet said drivers have been "thrown around on a year-long pump price rollercoaster" with prices fluctuating by up to 10p per litre.
He went on: "Families with cars react badly to price shocks, but worse still when falling wholesale prices aren't reflected at the pump.
"In the past fortnight, wholesale petrol and diesel prices have dropped but average UK pump prices have continued to rise."
RAC fuel spokesman Simon Williams said: "Diesel drivers especially will be relieved to see pump prices finally going down instead of up.
"While this is obviously welcome, it's important to realise that the drop in wholesale costs has been dramatic, meriting far bigger price reductions for both petrol and diesel.
"For this reason we view this round of cuts very much as a good start. We should really see more in the next week or so.
"We would very much like to see retailers reflect wholesale price reductions more closely.
This is particularly the case with diesel, which has been a similar price to petrol on the wholesale market for some time, yet is still 5p a litre more expensive on average on the forecourt."
Asda and Morrisons said the lower fuel prices will be effective from Thursday.
