How far apart are two forecourts in the same district?
Both prices come from the same postcode district on the same file, so the gap between them is what a driver who turned left instead of right would have paid. In most districts it is small. In a few it is enormous, and those are worth looking at rather than smoothing away.
Petrol E10, as published .
Petrol E10 — the gap inside a district
Across 1,374 districts holding 3 or more published petrol e10 prices, the median gap between the cheapest and dearest forecourt is 5.0p. One district in ten is at 16.0p or worse, and the widest is 70.0p. In 32 of them every forecourt publishes the same figure to the penny.
| District | Forecourts | Cheapest | Dearest | Gap |
|---|---|---|---|---|
| BS35 | 4 | 169.9p | 239.9p | 70.0p |
| CA10 | 6 | 171.9p | 230.0p | 58.1p |
| ZE2 | 7 | 154.5p | 210.0p | 55.5p |
| G71 | 3 | 149.9p | 199.9p | 50.0p |
| ST5 | 12 | 147.9p | 196.9p | 49.0p |
| BT32 | 14 | 132.9p | 179.9p | 47.0p |
| BT60 | 5 | 155.9p | 199.9p | 44.0p |
| LE3 | 12 | 155.9p | 196.9p | 41.0p |
| HD6 | 5 | 158.7p | 196.9p | 38.2p |
| CV23 | 4 | 159.9p | 196.9p | 37.0p |
| HS2 | 5 | 142.9p | 178.9p | 36.0p |
| RH11 | 3 | 160.9p | 196.9p | 36.0p |
Some of these are almost certainly somebody's decimal point rather than a forecourt charging it. We do not know which, so nothing here is dropped and nothing is called an error: each row links to the district page listing the forecourts, and both figures are the retailers' own.
Diesel B7 — the gap inside a district
Across 1,382 districts holding 3 or more published diesel b7 prices, the median gap between the cheapest and dearest forecourt is 6.2p. One district in ten is at 17.0p or worse, and the widest is 1745.1p. In 43 of them every forecourt publishes the same figure to the penny.
| District | Forecourts | Cheapest | Dearest | Gap |
|---|---|---|---|---|
| PO22 | 3 | 194.9p | 1940.0p | 1745.1p |
| LL21 | 3 | 107.9p | 198.9p | 91.0p |
| ST5 | 12 | 159.9p | 217.9p | 58.0p |
| ZE2 | 12 | 162.9p | 220.0p | 57.1p |
| BT32 | 15 | 142.9p | 199.9p | 57.0p |
| G71 | 3 | 167.9p | 217.9p | 50.0p |
| BT93 | 6 | 158.7p | 204.9p | 46.2p |
| KW16 | 3 | 159.9p | 204.9p | 45.0p |
| DN14 | 8 | 157.9p | 199.9p | 42.0p |
| LE3 | 12 | 175.9p | 217.9p | 42.0p |
| NW2 | 5 | 162.9p | 201.9p | 39.0p |
| HD6 | 5 | 179.7p | 217.9p | 38.2p |
Some of these are almost certainly somebody's decimal point rather than a forecourt charging it. We do not know which, so nothing here is dropped and nothing is called an error: each row links to the district page listing the forecourts, and both figures are the retailers' own.
Super E5 — the gap inside a district
Across 1,090 districts holding 3 or more published super e5 prices, the median gap between the cheapest and dearest forecourt is 14.0p. One district in ten is at 26.0p or worse, and the widest is 68.0p. In 11 of them every forecourt publishes the same figure to the penny.
| District | Forecourts | Cheapest | Dearest | Gap |
|---|---|---|---|---|
| NN6 | 4 | 197.9p | 265.9p | 68.0p |
| LE15 | 5 | 136.9p | 202.9p | 66.0p |
| PL12 | 4 | 155.9p | 209.9p | 54.0p |
| SO15 | 3 | 179.9p | 229.9p | 50.0p |
| ST5 | 11 | 160.0p | 208.9p | 48.9p |
| SG5 | 7 | 161.9p | 209.9p | 48.0p |
| CV23 | 3 | 169.9p | 214.9p | 45.0p |
| YO12 | 6 | 154.9p | 199.9p | 45.0p |
| B19 | 4 | 145.9p | 189.9p | 44.0p |
| BT8 | 4 | 131.9p | 175.9p | 44.0p |
| SK15 | 3 | 153.9p | 196.9p | 43.0p |
| ST1 | 6 | 156.9p | 199.9p | 43.0p |
Some of these are almost certainly somebody's decimal point rather than a forecourt charging it. We do not know which, so nothing here is dropped and nothing is called an error: each row links to the district page listing the forecourts, and both figures are the retailers' own.
Premium diesel — the gap inside a district
Across 619 districts holding 3 or more published premium diesel prices, the median gap between the cheapest and dearest forecourt is 10.0p. One district in ten is at 23.0p or worse, and the widest is 84.0p. In 7 of them every forecourt publishes the same figure to the penny.
| District | Forecourts | Cheapest | Dearest | Gap |
|---|---|---|---|---|
| S80 | 3 | 140.9p | 224.9p | 84.0p |
| BB5 | 4 | 158.9p | 224.9p | 66.0p |
| BT32 | 4 | 149.9p | 201.9p | 52.0p |
| NN6 | 4 | 220.9p | 265.9p | 45.0p |
| DD8 | 3 | 198.9p | 240.9p | 42.0p |
| LE3 | 8 | 189.9p | 229.9p | 40.0p |
| NW2 | 4 | 185.9p | 224.9p | 39.0p |
| BL6 | 3 | 200.9p | 238.9p | 38.0p |
| CV23 | 3 | 197.9p | 235.9p | 38.0p |
| BS20 | 3 | 193.9p | 229.9p | 36.0p |
| LU5 | 7 | 199.9p | 235.9p | 36.0p |
| NG9 | 5 | 199.9p | 235.9p | 36.0p |
Some of these are almost certainly somebody's decimal point rather than a forecourt charging it. We do not know which, so nothing here is dropped and nothing is called an error: each row links to the district page listing the forecourts, and both figures are the retailers' own.
Why three forecourts
A gap needs something to be a gap between. Over two forecourts it is a fact about two forecourts and reads as a fact about a market; over ten it would be a national page about a handful of cities. Three is the smallest floor with something in the middle. Petrol districts at each candidate:
| Forecourts publishing | Districts |
|---|---|
| 1 or more | 2,406 |
| 2 or more | 1,869 |
| 3 or more | 1,374 |
| 5 or more | 557 |
| 10 or more | 36 |
So this page is about 1,374 of the 2,406 districts holding any petrol price at all. 537 of them hold one forecourt, which has no spread — not a spread of zero, which is a different and real answer that 32 districts give. The remaining 495 hold two.
How this is measured →