Fuel could become cheaper than bottled water if the price of oil continues to plummet, motoring experts have said.
Oil prices have fallen by 30% since early December, with Brent crude sinking to 30 US dollars a barrel earlier this week.
Many analysts are predicting it could tumble even further, with Standard Chartered warning that 10 US dollars a barrel is a possibility.
The RAC said this could lead to UK motorists paying just 86p per litre (ppl) for fuel, as long as the pound does not continue to weaken against the dollar.
In December major supermarket fuel retailers cut petrol to under £1 per litre for the first time since 2009 - excluding promotions - while diesel was given the same treatment last week.
Average prices across the country are 102.5ppl for petrol and 103.2ppl for diesel.
RAC fuel spokesman Simon Williams said: "With no apparent end in sight to the freefalling price of oil, motorists can expect some really low fuel prices in 2016.
"Breaking through the pound a litre price point for both petrol and diesel was clearly a welcome landmark, but it looks as though there is more to come.
"In fact we may get to a bizarre time when a litre of fuel is cheaper than a litre of some bottled waters."
The motoring organisation claimed that diesel should have already been cut even more given current oil prices.
"Retailers still need to pass on more wholesale price savings on diesel to motorists at the pump, as the wholesale price is still 3p a litre cheaper than that of petrol," Mr Williams said.
"We should really be seeing diesel priced several pence cheaper than petrol on every forecourt, to the point where the average price of diesel goes below that of petrol."