What happened
The Department for Energy Security and Net Zero's weekly road fuel prices, published on 13 October 2026, put the UK average pump price at 200.04p a litre for diesel and 175.28p for petrol in the week of 12 October. A year earlier diesel was 142.99p. The diesel figure is the highest in the weekly series DESNZ publishes from 2018, just above the 199.22p of July 2022. The next weekly release is due on 20 October.
On 19 October Unite announced that more than 160 Apache offshore workers will strike for 24 hours from 6am on Wednesday 21 October, at seven assets linked to the Forties and Beryl fields, with a second 24-hour strike planned from 4 November. The union says the action could disrupt the Forties Pipeline System. Talks through Acas were scheduled before the strike. Energy Live News reported both stories together.
Why it matters for your carbon figures
Some small businesses work out vehicle emissions from the money spent on fuel, using a spend-based factor in kg CO2e per pound. That ties the result to the price. When the price jumps, the same budget buys fewer litres, and the same driving costs more. A spend-based figure gets both of those wrong.
The government's emission factor for diesel is per litre: 2.58354 kg CO2e per litre in 2026, whatever the pump price. Litres are what the engine burns, so litres are what to report.
A worked example
An illustrative firm puts £10,000 of diesel on its fuel cards in a quarter, at last year's and this year's average price:
| £10,000 of diesel at | Litres | Tonnes CO2e |
|---|---|---|
| 142.99p a litre (October 2025) | 6,993 | 18.07 |
| 200.04p a litre (October 2026) | 4,999 | 12.92 |
Same spend, about 29% fewer litres and the same cut in emissions. A spend-based estimate would show no change at all.
Now turn it round. A firm whose vans use 5,000 litres in both years emits 12.92 tonnes each time. But its fuel bill rises from £7,150 to £10,002, up 40%. Using Defra's spend factor for "Coke and refined petroleum products" (1.04558 kg CO2e per £ excluding VAT, 2023 figures), the estimate jumps from 6.23 to 8.71 tonnes, and neither figure matches the 12.92 tonnes worked out from litres. Nothing about the driving changed. If prices fall later, the same method will show a cut you didn't make. That is exactly the kind of false trend that confuses a baseline comparison.
What to do now
- Ask your fuel card provider for litres. Request a transaction report with the litres and fuel type for each fill-up, covering the whole reporting year, not just the invoice totals.
- Keep receipts for other fuel purchases. Till receipts show the litres. Collect them for fuel on company credit cards and staff expense claims.
- Use mileage where you have no litres. Our guide to company car and grey fleet emissions explains the per-mile factors.
- Keep fuel out of any spend-based Scope 3 estimate. Fuel counted in litres is already Scope 1, so it shouldn't be counted again from the ledger. Our post on spend-based Scope 3 covers what to leave out.
- Cut idling. The Highway Code (rule 123) says drivers should switch off the engine if a vehicle is likely to stay stationary for more than a couple of minutes, and the law forbids running an engine unnecessarily while stationary on a public road. Planning routes and combining trips cuts litres too. For a longer-term change, see the carbon payback of electric company cars and how HVO compares with diesel.
How Carbon Recycling helps
In Carbon Recycling you enter vehicle fuel in litres of diesel, petrol or LPG, and it applies the right year's government factor as Scope 1. The Company vehicles CSV template takes a fuel card statement in one go. When you import your accounting ledger, accounts named for fuel are spotted and left out of the spend estimate, with a prompt to enter the litres instead, so a price spike can't inflate your footprint. Our free kWh to CO2e calculator converts litres of diesel or petrol without an account, and the diesel factor page shows the figure for every year.
The environmental reason to care: every 100 litres of diesel your fleet doesn't burn avoids 258 kg CO2e. Counting litres is the only way those savings show up in your figures.