Generally, the least amount of engine oil you should have in your engine corresponds to the minimum mark on the dipstick. This is the least amount of engine oil that is safe to use without damaging the engine as determined by the vehicle manufacturer. You should always check the oil level when the engine is warmed up and has been sitting with the engine turned off for around 10 to 15 minutes. This will give the most accurate indication of the amount of oil in the engine.