Admittedly not my best early morning maths but, I do know a PHEV has a MPGe figure and a MPG figure from which you can extract a miles per kWh figure and get a more accurate account of overall economy. Likewise there are “x” kWh’s in a gallon of petrol however, I don’t think its as simple as dividing 21p into £6.27.
Untill my daughter goes back school my maths may as well be at gcse level!
I can’t remember what my % battery my ev range runs out but, its less than 20%. However, my conclusion is, the cars are learning how we drive and driving in the most efficient way it thinks best, based on the journeys we are doing. I will let you know in two weeks what % battery depletes to.
When you going away?