Just finished a rental at PHL. The vehicle had a fuel sensor that would read out via the Avis app in 1/10 gallon increments. The tank was at 7/8 full on departure which was on the contract. Upon return the tank had 1.4 more gallons and the receipt showed a fuel credit of [$4.13]

Other than that, the customer service at Avis PHL was abysmal due to severe understaffing and the Preferred office was closed.