TDI dieselDiesel pump prices fell by a hefty 5p a litre in July as fuel retailers belatedly passed on savings from a six-year low in the wholesale cost of crude oil.

The price of a litre of diesel dropped from 120.6p a litre at the start of July, revealed RAC Fuel Watch data, to 115.7p by the end of the month – and, on 29 July, the price of diesel dipped below petrol for the first time since 2001.

RAC fuel spokesman Simon Williams said: “July was a month of good news for motorists with diesel vehicles.

“The 5p a litre diesel saving recorded in July means the cost of filling up an average 55-litre diesel family car, such as a Ford Focus, has dropped by £3 in a month.”

Even better, RAC Fuel Watch data indicates more savings could be on the way if the price war between supermarket fuel retailers continues to run: “Pump prices should reduce to around an average of 111p a litre – a price last seen in January 2010,” said Williams.

“This would shave another £2 off a tank of diesel.”

Why is diesel getting cheaper?

The wholesale price of diesel is now 6p a litre less than petrol, reports the RAC.

Lower price have “been brought about by the fact two new refineries in Saudi Arabia are now producing diesel to meet the large European demand,” explained Williams.

“We expect this to be good long-term news for the nation’s 10.7m diesel car drivers as well as for businesses operating commercial vehicles.”

It’s not going to be a short-term saving in diesel prices, either. “Everyone should benefit from a better, fairer deal at the pumps going forwards.”

Has this changed the volume of diesel sold at filling stations?

Despite the anti-diesel sentiment earlier in 2015, HMRC reports sales of diesel fuel at the pumps is continuing to rise.

In June 2015, 2.5 billion litres of diesel were sold – that’s 4% up on May. Petrol sales were flat at 1.5 billion litres.

Note the difference in those two figures: Brits consume a billion more litres of diesel than petrol each month.

Look at the year-on-year difference and diesel’s advantage grows further: June 2015 diesel sales were up 5%, whereas petrol was actually down 4%.

The government also received £2.3 billion in fuel duty from combined diesel and petrol sales in June.

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