– The price of petrol continues to fall


– The RAC believe fuel could hit £0.86p a litre if the cost of a barrel of oil falls to $10, cheaper than all the biggest water brands


– Perrier, Highland Spring, Evian and Buxton might cost more than petrol by the end of the year


The price of crude oil has decreased to around $30 a barrel in the last couple of months and analysts predict it could go as low as $10.


If that happens, the RAC is predicting that the price at the pumps for both petrol and diesel would come down to around 86p a litre.


That would be the lowest level for almost seven years and down by almost 40% on the peak price of 137.3p a litre in March 2012.


With average monthly petrol use at some 107 litres, the cost would be just £92.02, which would be a saving of almost £55 a month compared to four years ago.


Some supermarkets have already cut the price of petrol and diesel to less than £1 per litre. The RAC said that if a barrel of oil falls to $20, pump prices should come down to around 90p a litre at supermarkets and other cheap fuel forecourts.


A one litre bottle of Buxton Still Natural Water retails at 90p.


The cost of a single 750ml bottle of Evian Still Natural Mineral Water is 83p, or the equivalent of £1.11 a litre, although the price comes down to 86p a litre for a pack of four.


A 750ml bottle of Highland Spring with a sports cap costs 82p, which is the equivalent of £1.10 a litre. A 750ml bottler of Perrier Sparkling is 96p or £1.30 a litre.


Since the beginning of December 2015, oil has decreased by 30% from $43.26 to a 12-year low of $30.06.