Here’s how car rentals work with respect to fuel:
— you can prepay, at a reasonable price per gallon. However, you are charged for a full tank, even if you return the car 1/2 full.
— you fill the car yourself, within a certain mile range from the rental return, and aren’t charged for fuel. FYI, ideally keep the receipt
— you don’t fill the car yourself, haven’t prepurchased the fuel, and are charged to refuel. In those cases, the cost per gallon IS approximately $10 per gallon.
Based on the fuel surcharged, she returned the car near empty. To figure out the mileage driven, multiply the MPG of that model times the tank capacity.
Who blacked out the return location, Tee or the reporter? That would tell whether she drove a maximum one way, or a round-trip to return to the same location. Given that there isn’t a one-way drop fee, my guess is she returned it to COS.