Petrol and diesel prices at Fitch's Service Station

Fitch's Service Station, HP5 1NQ.

What it is charging

Unleaded: 169.9p a litre, 1.8p under the national average, filed Thursday 29 October
Diesel: 199.9p a litre, 1.2p over the national average, filed Monday 26 October
Super diesel: 219.9p a litre, filed Monday 26 October

Asda Hall Park Express Petrol: 164.9p a litre, 4.6 miles away. 5.0p a litre cheaper: saves £2.75 a tank, and costs about £1.72 of fuel to get there and back. Worth the trip.
EG Chesham Pfs: 168.7p a litre, 1.8 miles away. 1.2p a litre cheaper: saves 66p a tank, and costs about 69p of fuel to get there and back. Not worth the trip.
Mfg Chesham: 169.9p a litre, next door away
Amersham: 169.9p a litre, 1.6 miles away
Chalfonts Way SF Connect: 169.9p a litre, 2.4 miles away
Amersham Superstore - Petrol Filling Station: 169.9p a litre, 2.4 miles away

On a 55-litre tank at 40mpg. The distance is straight-line rather than by road, so a real trip is longer than the one costed here.