Diesel Drivers Covering 10,000 Miles Now Pay £2,020 in Fuel, RAC Data Shows

• The RAC says the average price of diesel hit a record 200.01p a litre on 2 October 2026, the first time it has topped £2 and above the 199.09p set in June 2022.
• A 55-litre tank of diesel now costs £110.01, up £31.70 on 28 February 2026, while petrol costs £96.09, up £23.03.
• At 20p a mile for a 45mpg diesel car, a driver covering 10,000 miles a year now spends £2,020 on fuel.

The average price of a litre of diesel in the UK has topped £2 for the first time. RAC Fuel Watch data, released by the RAC on 2 October 2026, puts the national average at 200.01p. The all-time record has now been broken twice in a week: first at 199.18p on 28 September, then at 200.01p by 2 October.

For a driver, that turns into a simple bill. A 55-litre fill-up of diesel costs £110.01, which is £31.70 more than the RAC recorded on 28 February 2026, at the start of the US/Iran conflict. The RAC also worked out what the price means over a year. For an average 45mpg diesel car, the cost is 20p a mile, so a driver covering 10,000 miles a year is now spending £2,020 on fuel.

RAC head of policy Simon Williams called it “a pump price threshold that no-one wanted to cross”. This article sets out the RAC figures, adds clearly labelled calculations of what they mean at different mileages, and then looks at what a driver can do about it.

From 142p to 200p: What a 40 Percent Climb Does to a Year of Driving

The RAC’s own readings show how quickly the price has moved. On 28 February 2026 the UK average for diesel was 142.38p a litre. By the time the RAC warned that a record was looming, the average had reached 197.31p, just 1.78p short of the old high. It then reached 198.32p, then 199.18p on 28 September, and now 200.01p.

That is a rise of 57.63p a litre in a little over seven months, or about 40 percent (our calculation from the RAC readings). On a 55-litre tank, the same fill-up that cost £78.31 at the end of February now costs £110.01.

Petrol has climbed too, though by less. The RAC puts unleaded at 174.71p a litre on average, around 42p more than at the start of the conflict. A full 55-litre tank of petrol is £96.09, which is £23.03 more than on 28 February. By our calculation that is a rise of roughly 31 percent for petrol against 40 percent for diesel.

The gap between the two fuels is the part many diesel drivers will notice first. Diesel is now 25.30p a litre dearer than petrol, which adds up to £13.92 more on a 55-litre tank (£110.01 against £96.09). The RAC pointed out the irony: diesel cars, once seen as the most cost-effective choice for high-mileage drivers, are the ones now hitting owners hardest.

What a year of diesel costs at different mileages

The RAC’s 20p a mile figure comes from a 45mpg diesel car at 200.01p a litre. Using the same assumption, the annual fuel bill at four common mileages works out as follows (our calculations, at 20.2p a mile):

• 5,000 miles a year: about £1,010 in diesel.
• 8,000 miles a year: about £1,616 in diesel.
• 10,000 miles a year: £2,020, matching the RAC’s own figure.
• 12,000 miles a year: about £2,424 in diesel.

The same 45mpg car cost about 14.4p a mile to run on diesel at the 28 February price of 142.38p. Over 10,000 miles that is roughly £1,438, so the climb from that low point adds about £582 to a year of driving (our calculation).

Mileage and fuel economy both change the answer. A diesel car that returns 55mpg instead of 45mpg costs about 16.5p a mile at today’s price, or £1,653 over 10,000 miles. A petrol car doing 45mpg at 174.71p costs about 17.7p a mile, or £1,765 over the same distance. Put another way, a diesel driver whose car matches a petrol car’s economy now pays about £255 a year more for the same miles.

Tank size changes the bill at the pump too. At 200.01p a litre, a 40-litre fill costs £80.00, a 55-litre fill costs £110.01 and a 70-litre fill costs £140.01.

Who pays the most

The RAC singled out households and companies that cover a lot of miles: commuters, haulage and delivery firms, businesses with large fleets and sole traders. Those drivers fill up most often, so every extra penny a litre lands on them most often. The RAC also warned that businesses could have no choice but to pass the extra cost on to their customers.

RAC analysis of Fuel Watch data adds a second detail. Petrol is averaging 174.71p when recent retailing trends would put it nearer 170p. The RAC says that suggests some retailers are balancing prices across the two fuels to keep diesel a little lower. On a 55-litre tank, the gap between 174.71p and 170p is about £2.59 (our calculation), so petrol drivers are paying a small premium as well.

What could push prices higher

The RAC links the price to the conflict in the Middle East. In its 2 October statement it said there was no sign of a deal to reopen the oil and gas shipping route through the Strait of Hormuz. It also said US threats of a diesel export ban could push prices up further. In its 28 September statement the RAC added that another 5p a litre will be loaded onto pump prices by the spring if the current fuel duty cut is fully reversed as planned. Those are the RAC’s warnings, not a forecast from Motoring Chronicle, and the price could equally ease if supply improves.

Can You Avoid It? Practical Ways to Cut a £2,020 Diesel Bill

No driver can change the national average, but the average is a mean of very different prices. The RAC noted in an earlier statement that many forecourts were already charging well above the old 199.09p record. The steps below are the ones that put real pounds back in your pocket.

Check the forecourt before you fill up. The Competition and Markets Authority’s Enhanced Road Fuel Monitoring Report, published on 1 May 2026, found that diesel prices can differ by up to 17p a litre between forecourts within a 10-minute drive of each other. It also found a motorway premium of up to 17p a litre for diesel, and supermarket forecourts up to 11p a litre cheaper than non-supermarket sites. On a 55-litre tank those gaps are worth about £9, £9 and £6 respectively (our calculations).

Over a year the gains add up. A 45mpg car covering 10,000 miles uses about 1,010 litres of diesel (our calculation). Every 10p a litre you save is worth roughly £101 a year, and a 17p gap is worth about £172.

Improve your miles per gallon. Moving from 45mpg to 50mpg cuts the cost from about 20.2p a mile to about 18.2p, which saves roughly £202 over 10,000 miles at today’s price (our calculation). Correct tyre pressures, no roof box or rack when you are not using it, and smoother use of the throttle and brakes all push the figure in the right direction.

Business and company car drivers should check the mileage rate. HMRC’s advisory fuel rates from 1 September 2026 were built on a published diesel price of 179.2p a litre, about 21p below the RAC’s new average of 200.01p. HMRC reviews the rates every quarter, with the next update due for 1 December 2026, so there is a gap between what the rate assumes and what you pay at the pump. If your employer repays fuel at the advisory rate, keep your fuel receipts so you can see how far the two have drifted apart.

Know your own number. The RAC’s 20p a mile assumes 45mpg. Your own figure depends on your car, your tank size and your usual roads. Divide the cost of your last full tank by the miles driven on it and you have a real cost per mile you can compare with the RAC’s 20p. If yours is higher, the economy tips above are the quickest place to start.

The RAC publishes fuel prices through its Fuel Watch service and its myRAC app, which also lists cheaper nearby forecourts. The next Fuel Watch update will show whether the £2 mark was a peak or the start of another leg up. Until then, the sums above give diesel drivers a clear idea of what each mile now costs.

Sources:

• RAC Media Centre: Diesel tops £2 a litre for first time ever (2 October 2026)
• RAC Media Centre: Price of diesel reaches record high