Costco gas at Kahului is really more for locals than tourists. When you rent a car, it comes full of gas, you stop for staples and necessities at Costco enroute to your timeshare. On the way back to catch a flight, you don't need anything at Costco to carry home. Are you likely to risk a long line to fuel at Costco or leave early enough to wait in one just to save at most $2.00- $3.00 on the gas before you turn in your car? Not me. I get gas at Lahaina. The gauge still reads full at turn in, and the miles to Kahului are freebies.
Jim