The amount of gas a car can hold depends on the size of the car's fuel tank. Fuel tank sizes vary widely, from as small as 10 gallons to as large as 35 gallons. The average fuel tank size for a passenger car is around 15 gallons. Here are some examples of fuel tank capacities for different types of vehicles:
* Small cars: 10-12 gallons
* Mid-size cars: 13-15 gallons
* Large cars: 16-18 gallons
* SUVs: 18-22 gallons
* Trucks: 20-35 gallons
It's important to note that these are just general guidelines. The actual fuel tank capacity of a particular vehicle may vary depending on the make, model, and year of the car.