Methodology
Oil Stock Levels
Stock data comes from DESNZ Energy Trends Table 3.11 (Stocks of Petroleum), published monthly. The data covers closing stock levels at UK refineries, terminals, and offshore facilities.
We track four product categories:
Petrol — Motor spirit (column: "Petrol")
Diesel — Total diesel/gas oil (DERV + red diesel, column: "Total diesel/gas oil stocks")
Jet Fuel — Aviation kerosene (column: "Jet fuel")
Heating Oil — Burning oil (column: "Burning oil")
Units are thousand tonnes (kt). Data is published with an approximate 2-month lag — for example, January 2026 data was published in late March 2026.
Days of Supply Calculation
Days of supply = (Stock level ÷ Monthly consumption) × 30
Monthly consumption comes from DESNZ Energy Trends Table 3.13 (Deliveries of petroleum products for inland consumption). Where consumption data for the exact stock period is not yet available, we use the most recent available month within 3 months.
The 90-Day Benchmark
The UK is an IEA member and is obligated to maintain oil stocks equivalent to at least 90 days of net oil imports. Post-Brexit, this obligation is maintained through retained EU law (Council Directive 2009/119/EC). The IEA conducts regular reviews of member country compliance. UKOilWatch uses 90 days as the reference benchmark throughout the dashboard.
Important: The 90-day figure refers to net imports, not total consumption. Because the UK is both a producer and importer of oil, the days-of-supply figures shown on this dashboard (calculated from total consumption) are not directly comparable to the IEA compliance figure. They indicate domestic buffer capacity rather than formal compliance.
Weekly Fuel Prices
Pump prices come from the DESNZ weekly road fuel prices dataset, compiled from the CMA Road Fuel Prices Scheme. This covers approximately 90% of UK retail fuel volume. Prices are national weighted averages in pence per litre, including duty and VAT.
Brent Crude
Brent crude oil futures (BZ=F) are fetched from Yahoo Finance. The price updates client-side every 5 minutes when the dashboard is open.
AI Analysis
A daily AI-generated analysis is produced using Claude (Anthropic). The model receives the latest stock, price, and crude oil data and generates a plain-English summary. The analysis is clearly labelled and timestamped. It may contain errors and should not be relied upon for critical decisions.
Data Pipeline
An automated pipeline runs daily via GitHub Actions. It downloads the latest DESNZ spreadsheets and price CSV, processes the data, generates the AI analysis, and commits updated JSON files to the repository. The site rebuilds automatically on each commit.
Limitations
Stock data has an inherent ~2-month lag from DESNZ publication schedules
Days-of-supply figures use total consumption, not net imports — see note above
Prices are national averages; regional and forecourt-level variation exists
The DESNZ spreadsheet URLs change with each publication — the pipeline scrapes for the latest
AI analysis may contain errors or misinterpretations