Should I check the engine oil level when it is warm or cold?

Aresea,

It is best to check the engine oil level when it is warm rather than cold. The reason is because oil will contract when it is cold and expand when warm. Although this may lead you to think that checking when cold will give you a lower reading and indicate that you need to refill your engine oil, you need to understand that when you use your car, the engine will heat up and expand the oil and as a consequence, the higher reading is much better to prevent you from over-filling the oil tank.