Every Diesel Driver Pays 20p a Mile, RAC Finds, With Pumps Near £2

• RAC analysis puts diesel at 20p a mile for a car that manages 45mpg, with the average litre at 198.42p.
• Driving 8,000 miles costs about £1,605 a year in diesel, while the 3p a mile electric car charge due from April 2028 adds £240 on the same distance.
• Duty and VAT make up 43 percent of the pump price, which is 8.69p of every 20p mile.

A 150 Mile Week in a Diesel Now Costs £30.09 at the Pump

Diesel drivers spend 20p on fuel for every mile, and the official pump data backs the RAC sum. The RAC puts the average litre at 198.42p and the typical diesel car at 45mpg. The Department for Energy Security and Net Zero (DESNZ) records 198.58p a litre for the week starting 2 November. Either price lands on 20p a mile.

The working takes four lines. A gallon is 4.54609 litres, so a gallon of diesel at 198.58p costs £9.03. A car that covers 45 miles on that gallon spends 20.06p a mile. At the RAC’s 198.42p the answer is 20.05p. A 100 mile trip costs £20.06 and a 150 mile week costs £30.09.

The price sits close to a record. DESNZ has published weekly pump averages from January 2018 onwards, and diesel peaked at 200.04p a litre in the week starting 12 October, the highest weekly figure in that series. A mile cost 20.21p at the peak. Prices have eased only 1.46p from that peak, so the 20p bill has barely moved.

The climb is recent. In the week starting 2 March diesel averaged 142.15p, which made a mile cost 14.36p at the same 45mpg. The next week brought a jump to 149.01p, and by 12 October the litre price had risen 57.89p. Seven weeks ago, in the week starting 14 September, it stood at 190.72p. It is 7.86p higher now, and every weekly reading from 28 September onwards has stayed above 197p.

A longer view makes the point sharper. In the first week of January 2018 diesel averaged 123.51p a litre, with fuel duty at 57.95p. At 45mpg that was 12.48p a mile and £998 over 8,000 miles. Today’s mile costs 7.58p more, even with duty 5p lower than it was then.

What a Year of Diesel Mileage Costs

At 20.06p a mile, 8,000 miles of diesel costs £1,605 a year. A driver doing 10,000 miles pays £2,006 and one doing 12,000 miles pays £2,407. These are the site’s own sums from the DESNZ price and the RAC’s 45mpg, and they cover fuel only. Spread over twelve months, 8,000 miles comes to £133.74 a month.

The 20p is an average, and the car decides where a driver lands. A diesel returning 40mpg spends 22.57p a mile, or £1,806 over 8,000 miles. One returning 50mpg spends 18.06p, or £1,444. The gap between the two is £361 a year on the same road and the same pump. City driving pushes the figure higher, and so does any forecourt charging above the average.

A year ago diesel was far cheaper. DESNZ puts diesel at 142.61p in the week starting 3 November 2025, which is 14.41p a mile. Today’s price is 55.97p a litre higher, a rise of 39 percent. The same 8,000 miles costs £452 more than it did twelve months ago. A 55 litre tank costs £30.78 more, in line with the diesel tank premium over last year that DESNZ data showed in October.

Where the Pound Goes: 43 Percent of the Pump Price Is Tax

Fuel duty is 52.95p a litre on both petrol and diesel, and VAT is charged at 20 percent on top of the product and the duty. At 198.58p a litre the pump price contains 33.10p of VAT and 52.95p of duty. That is 86.05p of tax, or 43.3 percent of every litre.

Converted to the mile, tax takes 8.69p of the 20.06p. Duty accounts for 5.35p and VAT for 3.34p. The remaining 11.37p a mile pays for the fuel itself, which is 112.53p of each litre before tax.

The latest Budget extended the 5p fuel duty cut, which holds duty at 52.95p. With VAT added, that cut is worth 6p a litre, or 0.61p a mile. Over 8,000 miles it saves a diesel driver £48. The freeze protects against a rise but gives no relief from the 20p already on the meter, and diesel drivers still pay the full 8.69p of tax on every mile they cover.

How Petrol and Electric Compare Mile for Mile

Petrol is cheaper to run at the pump. DESNZ records unleaded at 172.78p a litre for the week starting 2 November, which is 17.45p a mile at the same 45mpg. That costs £1,396 over 8,000 miles, £209 less than diesel. Petrol cars often return different mpg from a diesel, so the comparison is like for like only on that assumption. The gap at the pump is clearer: diesel costs 25.80p a litre more than unleaded, which adds £14.19 to a 55 litre fill.

Electric cars sit in a different range. Charging at home usually costs between 2p and 8p a mile, depending on the tariff and the car, which is £160 to £640 over 8,000 miles.

A mileage charge for electric cars is on its way. HM Treasury confirmed in its July 2026 consultation response that electric vehicle excise duty starts in April 2028, 17 months from now, at 3p a mile for fully electric cars and 1.5p a mile for plug-in hybrids. The Treasury says electric drivers do not pay an equivalent usage-based tax today and describes the 3p rate as half the equivalent fuel duty rate. The charge is paid on top of the electricity, so the site’s arithmetic for an electric car is 5p to 11p a mile. Over 8,000 miles that is £400 to £880, which is £725 to £1,205 below the diesel bill. The charge alone comes to £240 on that mileage, and the Treasury’s own worked example for a 5,000 mile year at 3p is £150. A plug-in hybrid doing 8,000 miles would owe £120 at 1.5p. Anyone thinking about a switch can read what the electric car mileage tax means in practice before April 2028.

What Drivers Can Do, and What Comes Next

Pump price and fuel economy are the two levers a driver controls. A litre priced 5p cheaper takes 0.51p off every mile and saves £40 over 8,000 miles. A car that improves from 45mpg to 48mpg spends 18.81p a mile and saves £100 over the same distance. Every 1p on the litre price moves the 8,000 mile bill by £8.08, so a move in the weekly DESNZ figure shows up quickly.

Rod Dennis, the RAC’s senior policy officer, said the latest Budget offered little else:

“While drivers may breathe a mild sigh of relief knowing that fuel duty isn’t going up, many are likely to be disappointed the Chancellor didn’t go further to support them.”

He added that drivers wanted more help:

“RAC research published yesterday showed nearly two-in-three regular drivers wanted cuts to duty or VAT on fuel, with a similar proportion now cutting back on other spending because of the high cost of fuel.”

“A freeze only avoids making an already difficult situation worse – it doesn’t make filling up any cheaper. And it’s worth remembering that pump prices still soared this summer, despite fuel duty being at this very same reduced rate.”

“Drivers will now have to hope for an easing of the international conflicts that have pushed up oil prices and disrupted fuel supplies if pump prices are to come down in a meaningful way.”

His advice for drivers in the meantime was to use the forecourt price tools:

“In the meantime, they can ensure they always pay the lowest price for filling up by using the free myRAC app to locate the cheapest forecourts up and down the country.”

DESNZ publishes a new weekly price every week, and each one resets the sum. Duty stays at 52.95p, so the next movement in the 20p a mile figure comes from the oil price and the forecourt a driver chooses.

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Sources

• DESNZ: Weekly road fuel prices
• HM Treasury: The introduction of Electric Vehicle Excise Duty (eVED) Consultation Response
• Express: Diesel drivers face 20p per mile charges in November

Reviewed by Preetam Gadekar