[somerandomguy]

I think that filling up until diesel visible in tank filler neck is more reliable than clicks on gas pump because these have a hole whth a tube that is full of air and when the tube gets gas in it it is designed to click and shut off gas flow. This can happen with splash back when gas exits quickly from nozzle and bounces back and trips the cutt off mechanism without the tank being full, foam can also trip the cutoff mechanism when gas is poured quickly as this creates foam , it could be more beneficial to let the flow of gas out of nozzle be slow to avoid clicking of gas pump due to splash back and foamy fuel.

Would a tachometer help with fuel economy?