I should have added that sometime this week I’m going to empty the car of everything, including the child seat, loose change and junk lying in the boot. Check tyre pressure, get a dry day and go on a drive of motorway at 60mph, A & B roads at 40 mph and city driving around 20mph and drive as conservatively as possible with lights off, no heat, radio and see if I can get over 6 for the whole journey. About 40 mile motorway, 10 mile A&B and 2 mile stop start city driving.