@glos guy Wow, if you are only getting 479 miles and spending £17 on charging, you are doing something wrong, or your sums are incorrect. If you vehicle has a battery and an electric motor, like my one does…i get 900 miles out of £17 of charge. A few guys on here have only used one tank of petrol in 6 months of ownership. Granted. Ot everyone can run their phev purely on charging, but some can. Your figures for 479 miles are horrible.
E10 unleaded petrol has a shelf life of 3 months it then start to deteriorate, if you are using one fuel tank every 6 months on a PHEV you have the wrong vehicle i.e a full EV
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.