Typically, delivery trucks have gas tanks that can hold anywhere from 20 to 50 gallons of gas. Smaller delivery trucks, such as those used for local deliveries, may have tanks that hold around 20-30 gallons while larger delivery trucks, such as those used for long-haul deliveries, may have tanks that can hold up to 50 gallons or more.
Additionally, some delivery trucks may be equipped with auxiliary fuel tanks, which can increase the total fuel capacity of the vehicle.