Fleet Fuel Bill Index
UK diesel pump prices rebased to 100 at the first full week of 2026 — a single number for how much a diesel fleet's fuel bill has moved this year.
UK diesel cost 182.82p per litre in the week ending 24 August 2026 — a Fleet Fuel Bill Index of 109.4, 9.4 points above its January 2026 base of 100 (THRIVE, from DESNZ).
Cite this
THRIVE Fleet Fuel Bill Index, week ending 24 August 2026. thrivefleet.co.uk/data/fuel-bill-index (accessed 1 September 2026).
The index this year
100 = first full week of Jan 2026
| Category | Value |
|---|---|
| 20 Jul | 100 |
| 27 Jul | 104.1 |
| 3 Aug | 107.2 |
| 10 Aug | 108.9 |
| 17 Aug | 108.6 |
| 24 Aug | 109.4 |
Where it stands
vs January base
| Category | Value |
|---|---|
| vs Jan 2026 base | 109.4 |
Pump prices in pence per litre are hard to feel. Rebasing them to an index — 100 at the start of the year — turns the same DESNZ data into a running tally of how much more, or less, a diesel fleet is paying to fill up than it was in January. An index of 105 means a 5% heavier fuel bill for the same mileage.
It is the diesel-side counterpart to the Fleet Cost Index: one tracks the absolute cost gap to electric, this one tracks how the diesel bill itself is trending.
Base: the diesel pence-per-litre of the first DESNZ weekly figure on or after 5 January 2026 — 167.08p. Each week's index is 100 × that week's diesel price ÷ the base. The base is set once from real data and never recomputed.
Source: DESNZ weekly road fuel prices under the Open Government Licence v3.0. The base reads live from the rates API.
Figures checked against GOV.UK on 1 September 2026.
Free JSON API — no key, open CORS, cache-friendly:
curl https://www.thrivefleet.co.uk/api/v1/fuel-bill-index{ "unit": "index (100 = base week)",
"weeks": [ { "week": "…", "index": …, "diesel_ppl": … } ] }Attribution is requested, never required — see the data terms and the API guide.
How much have UK fleet fuel costs risen in 2026?
On the Fleet Fuel Bill Index — diesel rebased to 100 in January — the latest reading is 109.4, 9.4 points up on the start of the year.