Whether you have a sedan or a truck, your car has a set oil intake. If you plan to do your own oil change, you first need to determine your car's engine oil capacity. You don't want to overfill it because the oil may find its way into parts of the engine where you don't want it to go. You also don't want to under fill it either, since you may find the engine under lubricated and subject to overheating.
How much oil a car requires is determined by the make and model of your vehicle. Most engines require anywhere between 5 to 8 quarts of oil, depending on your car's engine size. The smaller the engine, the less oil required to fill the volume of the engine.