I'm off on holiday tomorrow so thought I would top off tank (with Shell V-Power! It only drinks premium fuels), it was showing 1/4 tank down. £42 later my foot was on the floor trying to work that one out. I'm pretty sure the tank doesn't take £160 of fuel from memory - even with cognac in the tank. So either I got burned in the petrol station or my gauge is not very accurate. Best not get low on fuel as I wouldn't trust the dial.
With this car I neither check the petrol prices or pay attention to how much it cost, or when I last filled up! I just have to have this car so cost irrelevant. Not interested in calculating MPG. My other cars I watch like a hawk!