my last 2 tanks, I went into the yellow, and dte was down to 20's. both times I filled up (I fill up every tank), and it took less than 16 gallons. being that we have a 19.5 gallon tank, this seems a bit odd to me. I get gas every 2 days, as my commute to work is 73 miles each way. I'd like to eek out as much as possible!