A 12 month oil low of $41.87 at the end of August helped to bring the average price down by 4p a litre, according to RAC information.æ Diesel prices also continued to drop, with 5p overall being shaved off per litre throughout the month. Overall, motorists are now paying around £2 less to fill up a family car than they were at the beginning of the month. The fall in prices is almost entirely due to the substantial reduction in the wholesale price of oil.æ In July, the barrel price was a fairly consistent ($60), but immediately dipped down to below $50 and the beginning of the month and stayed there, reaching a low of $41.87 on the 24th August. Simon Williams, the RAC fuel spokesman, said: 'We thought July had been a good month for motorists but August proved to be better still due to world oil prices reaching their lowest since February 2009. 'In January, we saw oil go down to $45 but then recover to around the $60-a-barrel mark where it stayed for several months until this new level of over-production in August led to a dramatic reduction. 'Diesel drivers have benefitted the most this summer due to a new supply of diesel from Saudi Arabia bringing the wholesale price down. 'They are now paying £5.60 less to fill up than they were at the beginning of July whereas the savings for petrol motorists have only just kicked in with the drop in the price of oil feeding through into lower wholesale and retail prices. HMRC oil duty statistics showed that overall fuel sales were 1.6 per cent down on June, with an overall 2.4 per cent drop in the litres of diesel sold, falling from 2.494bn to 2.433bn.