Petrol below £1 a litre returned today when supermarkets Asda and Morrisons dropped the price of unleaded to 99.9p.
Falling prices also mean a boon for air passengers, with falling fuel surcharges.
For motorists, the Asda cut means a 5p a litre reduction in the price of petrol , with a litre of diesel falling from 116.9p to 110.9p. Petrol is the same price at Morrisons but diesel is a penny dearer.
This is the first time since last December that unleaded has been under £1 in the UK, with unleaded going over 120p a litre and diesel over 130p during the worst of this year's price rises.
Asda spokeswoman Jennifer England said: "Unlike some of our competitors, our price is constant throughout the country and does not vary from area to area. This reduction will come as a relief to road users."
Morrisons said its new prices would apply at all its 287 UK forecourts and that this was the sixth time it had cut petrol prices since July.
The price of oil on world markets has fallen from a high of around 147 US dollars a barrel earlier this year to as low, last week, as less than 80 dollars.
Last week Prime Minister Gordon Brown said he wanted this price cut to be passed on to consumers "as quickly as possible".
And today oil prices slid to their lowest level for nearly 14 months amid concerns that the world economy is heading for a major slowdown.
Light, sweet crude for November delivery on the New York Mercantile Exchange (Nymex) was trading more than three dollars lower at 75.10 US dollars a barrel.
Prices dipped as low as 74.97 US dollars at one point, the lowest since the start of September last year.
Damien Cox, senior analyst at energy adviser John Hall Associates, predicted further falls as the outlook for the worsening economies becomes clearer over the coming months.
He said: "With the economic situation looking the way it is, I don't think we have seen the bottom yet. There's still a little bit to come out of this over the next few months."
Today's fall in oil prices was reflected on the stock market, with shares in BP sliding nearly 4 per cent. Rival Royal Dutch Shell fell by the same amount.
For air passengers, the good news came after British Airways today joined rival carrier Virgin Atlantic in reducing passenger fuel surcharges.
Last night Virgin announced it was cutting charges for its economy and premium economy passengers from midnight tonight.
Today, BA said it was reducing surcharges for its economy class (world traveller) and premium economy (world traveller plus) passengers on long-haul flights.
The economy-class changes will mean that the surcharge for long-haul flights of more than nine hours will drop by £13 per flight from £109 to £96.
The economy-class surcharge for long-haul flights of less than nine hours will drop by £10, from £78 per flight to £68.
For premium economy passengers on long-haul flights under nine hours the charge comes down from £88 to £83, while for flights of more than nine hours it is reduced from £121 to £114.50.Reuse content