The car has gone in for further diagnostic work this morning to work out exactly the issue with the fuel mix. It's likely a faulty or blocked sensor so shouldn't be too expensive to fix. 😉
I'm looking forward to getting out on the walk after work – as long as the weather holds. It's supposed to be okay.
I completed the walk, submitted my screenshot from Strava and jumped straight in the shower.
I've always been quite a quick walker and kept a good pace, but am horribly unfit and don't mind admitting that things started aching a bit towards the end.