Thanks for the information. I start my drive back north tomorrow and will keep track as well. So far I have found my low fuel light comes on at about 30-33 gallons left. I spoke to Spartan about it and they said they prefer to play it safe about fuel gauges and making sure we don't ever draw the last five gallons. From a "fear" perspective it works since my gut reaction to a low fuel light is to always fill up soon. I guess I will approach it as a nice safety margin if I am ever further away from fuel than I planned for.
2012 Entegra Aspire 40DRQ on Spartan chassis
2006 Toyota Highlander toad
2 daughters, 2 dogs, and 1 wife