The display only measures a voltage. What Charles is saying is that both gauges use the same resistance wire per unit length. I.e. for any given drop they both read the same resistance/voltage. Therefore they both read full at the top, and they both read zero at the same level down the sender. The longer unit will continue to vary voltage as the level decreases, but at this point the display will already be reading zero.
2012 G56 Stage 2 M3W 2007 Fiat Panda 100HP 1998 Lotus Elise (Cosworth Duratec) 1988 RF88 Van Diemen
