Yes, UCAR vehicles must be returned with no less a 1/2 tank of gas. If you are within 5 miles of campus, refuel at Fleet Services (4659 25th Ave NE, next to University Village).
Every UCAR also comes with a WEX fuel card, for those times you’re further away. This credit card can be used at any major gas station. When prompted, enter your Driver ID number, which is the first five digits of the vehicle license plate number plus “0”. For example, if your license plate is 12345E, your Driver ID number is 123450. You will also be asked to enter the current vehicle mileage (not trip meter reading). Submit all receipts to email@example.com.
More information: Fueling vehicles and WEX Fuel Card use