Thanks for the advice, always appreciated.
I thought as much re their utter nonsense! They’re currently asking me to get an alignment done on the vehicle at their cost and then they may even consider replacing the tyres, so I’ll let them carry on for now.
you may have a point re the rolling resistance it’s also been mentioned in comments previously by my mechanic, that may just be the cause.
I still haven’t reset the gears either yet as I was worried it may make the miles even worse but I guess I can give that a go too.
thanks