Two-car families in the UK could pay around £8 a month more to fill up their cars if Britain leaves the EU, the RAC has claimed.
The motoring organisation calculated that a 20% fall in the value of sterling - as US banking giant Goldman Sachs has predicted could happen after a Brexit vote - may increase the average price of a litre of petrol by around four pence.
The analysis found that this would mean a household with two 55-litre petrol cars refuelling twice a month would spend £232 a month compared to £224 today, based on average prices.
Simon Williams, the RAC's fuel spokesman, said: "While the RAC has no view on the UK's membership of the EU, the impact on fuel prices of Britain leaving is not likely to be as dramatic as motorists might be led to think.
"While the strength of the pound is a significant factor in the price motorists pay for petrol and diesel due to wholesale fuel being traded in dollars, the oil price is currently a greater influence.
"Despite talk of a slight curb in oil production this week the price of a barrel has remained stable."
The AA claimed that a vote to leave in the upcoming referendum could mean two-car families paying £494 more for petrol a year if a 20% fall in sterling coincided with a rebound in the price of oil to more than 90 US dollars.
It said this could occur if Opec does agree production limits and US drivers continue to increase petrol consumption.