Industry analysts have predicted the price of oil could plummet to just $20 a barrel - around £13 - which would be the lowest price since 2002.
If their forecast is correct it could be catastrophic for the North Sea oil industry which has already shed 65,000 jobs.
But motoring groups said it would be good news for consumers, with unleaded already as low as 105.9p per litre.
The slump would also prove beneficial for homeowners and many industries - apart from the North Sea sector, which is shedding jobs and shelving projects at an alarming rate.
Last night, RAC spokesman Simon Peevers said car owners would benefit greatly.
He said: “If the price of oil came down to $20 a barrel we would see a significant drop at the pumps.
“We will see it below £1 a litre. It has already come down below £1 once, so it is a real possibility.”
US investment bank Goldman Sachs warned the price of oil, which has already plunged to less than $44 (£28) from $107 (£69) last June, could now drop to $20 a barrel - its lowest in 13 years. Economist Alice Enders, of London-based Enders Analysis, said a plunge to $20 a barrel would not be inconceivable, which would make it “extremely difficult” for the industry to survive.
“I think it’s possible but it doesn’t mean it’s certain and I’m hopeful unknown events will intervene to keep the price trending where it is now, rather than falling more,” she added.
Last week, figures contained in an Oil and Gas UK report found the number of direct or supply chain jobs in the oil industry have fallen 15 per cent, from 440,000 in the UK at the start of last year, to 375,000.
It prompted Scottish Labour public services spokesperson Jackie Baillie to accuse the SNP government of failing to act.
She said: “We need the full resources of the Scottish Government directed towards this jobs crisis, no matter how embarrassing it might be for them politically.”
Meanwhile, a separate study has revealed the oil price slump is having a big impact on the wider Scottish economy. The latest monthly survey from accountancy firm BDO found the hotel occupancy rate in Aberdeen decreased for the third consecutive month.
The Scottish Government said: “Our oil and gas bulletin, published in June, confirmed that Scotland remains, by some margin, the biggest oil producer in the entire EU.
“Recent provisional figures from the Department of Energy and Climate Change suggest that May saw the most oil and gas produced in the North Sea since March 2012. If this trend is sustained, production could increase this year for the first time in 15 years.
“But it is vital that the UK Government makes good on its commitment to introduce further measures to support exploration and allow newly discovered fields to come on-stream.
“We are doing all we can to support oil industry workers and their families.
“Oil, however, is a bonus, not the basis of Scotland’s economy. Even without it, Scotland’s output per head ranks third of the 12 countries and regions of the UK behind only London and the south-east.
“The tumbling oil price means good news for motorists filling up at the pumps - but bad news for the North Sea industry.”