I have the petrol version and we did calais to disneyland Paris and back again in one tank, it would of been well into the 40’s mpg wise and had about 70 miles left. Mind is was 60 and 50 most of the way but its possible! My advice would be avoid the cloth seats ( I think the phev has micro suede as standard ) but ours has no lumbar support and long journeys are followed by a good bout of back ache, apart from that it’s been solid. Oh and test drive it if you’ve not already as the cvt box is not too everyone’s liking.