Ok I will give you an example towing a 1500kg caravan back from the New Forest 181.7 miles from site to home, 13.6 kWh £2.04 Fuel 25.75 litres £35.77 (£1.39 litre) Total £37.81, now covert that back to litres (37.81 divide by 1.39 = equivalent to 27.20 litre) 27.20 litres divide by 4.546 = 5.98 gallons. 181.7 miles divide by 5.98 gallons = 30.38 mpg.
349 miles total
£5.20 electric cost taking into account 0-100% charge for ease.
£34.09 fuel cost.
Total £39.29 convert back to litres 39.29 / 1.39 = 28.26 litre
28.26 / 4.546 = 6.22 gal
349 / 6.22 = 56.1 mpg
If I then want to work out pence per mile from the calculated mpg (56.1), I would assume I calculate this as:
(Petrol price in pence / 100) ÷ (MPG / 0.22)
(137.5 / 100) / (56.1 /0.22)
1.375 / 255 = 0.005 pence per mile ???
Surely the correct way to do this, is find the total cost for journey and divide by the number of miles?
(34.09 + 5.20) / 349
£39.29 /349 = 11.2p per mile ?
Your help is much appreciated mate 🙂