@kezo I did a 240 mile round trip with the tyres inflated to 38 PSi as you suggested. Unfortunately it didn’t seem to help the mpg. Allowing for the cost of the full charge that I started with, I averaged just 38mpg. For most of the journey I was on motorway and A roads at around 73mph. My previous petrol BMW would have easily achieved 45mpg on that journey.
Over the next few months we have two short breaks where I will be doing circa 400-600 miles, each with just a charge to start and the vast majority of the mileage being in HEV mode which, as we know, is fuel inefficient, so I dread to think what they will turn out like. Probably low 30s. After that I think I’m going to stop working out the real running costs as it keeps reminding me that, for us, a PHEV was a poor choice 😂