Why are there no gas gauges in Nascar race cars?

Nascar cars do not use normal gas gauges due to the fact that when the cars are in corners the centrifical force causes the fuel to slosh around in the fuel cell, Which in turn would cause the gauge to sometimes show that it is empty and sometimes full. That is why they use fuel pressure gauge instead. Which tells the driver how they are doing on fuel via the needle bouncing back and forth.