I am not sure you can or must fully drain your tank,,, An honest attempt to have as near an empty tank as possible should be OK,,, Yes 5 gallons of race gas will cost between $45 a $60 depending on the blend you select.
ECTA is all about INTEGRITY... we hope if you can't fully empty your tank you will be close to empty and buy the track gas from our vendor.. they also assume what gas you drove in on is "pump gas" and not "dosed". once again personal accountability and integrity ...
See you Saturday.
Charles