@kezo Interesting to see how your mileage breaks down and that completely explains why we are getting different results.
You are doing 400 miles of local journeys a month which are all within the EV range. My monthly journeys that are 100% within EV range are less than half of that.
Our longer journey mileage is probably similar, but yours is one very long journey every 3 weeks, whereas mine is a 60-100 mile journey weekly.
I think that, extremes aside, we are probably getting similar mpg equivalent on the local journeys and I am getting slightly less than you on the longer runs as my average speed is higher (due to motorways).
Our respective experiences in the same car proves that the decision on whether a PHEV is right for someone heavily depends on what proportion of their total mileage is going to be within the EV only range, as EV mileage works out very cheap, but on longer journeys when the battery is depleted there is no advantage over a fuel efficient ICE car. I stress that I am still making a very small saving (up to £20 a month) over the BMW, but I’d personally sacrifice that £20 not to have to plug the car in after every use!