Motoring chiefs call for supermarkets to cut price of fuel by 5p per litre Asda's price cuts took unleaded at its forecourts down to a maximum of 133.9p with diesel at 138.9p per litre. Across the UK, unleaded averages 138.8p per litre with diesel at 142.88p. Today's push by the RAC came as the rate of inflation dropped to 2.7 per cent from 2.8 per cent in July. The official figures put the drop down to a slower increase in petrol prices and air fares in August than the same month last year. Inflation as measured by the broader Retail Prices Index rose from 3.1 per cent to 3.3 per cent. In June this year, the RAC said nine out of ten UK motorists felt they were "sitting ducks" for the Treasury, which collects more than £40 billion a year in taxes on fuel and road duty. Some 77 per cent of motorists claimed they were struggling to make ends meet because of the soaring cost of fuel.