McChaps and l,l,lady
Something weird happed - went for a spin in Cornwall like you do, car said just over 1/2 a tank full and 500 odd mile till empty (life is good) came back from the beach after a surf check and car said 1/4 200 odd miles till empty

sucks has some little scrot just taxed my tank I was only gone for twenty mins. Stopped applied the SIOAOA protocol a couple of times the same, arrhaghgh not that diesel is expensive but arrhhh lost 1/4 tank. Later on after lunch and a chill out car said yeah I was just messing with ya you got just over 1/2 a tank; WTF now I just dont trust you, maybe you have a hint of the electrical sickness - hmmmm
Has anyone experienced similar fuel gauge wobbles of such magnitude?
Thought the sender could be dickie - ?