I did a 349 mile trip, of which 38 miles of those were electric. It worked out at 56.6mpg 11.2p a mile.
I don’t know if its feasable to take 38 miles of total trip and divide that by 6.22 gallons (£34.09), to take into account of not charging the battery. 311 /6.22 = 50mpg @Glos-Guy