No-Toil Oil Check

The first and foremost rule is that you check the oil while the vehicle is on level ground. Since the dipstick extends into the engine oil pan, it cannot give a correct reading if the oil is collected at the back, front, or sides of the oil pan. The second rule is to wait long enough for oil to drain back into the pan before checking. This can be as short as five minutes, or as long as overnight.

Hot and Cold
There is an ongoing argument as to whether or not it is better to check your oil when the engine is hot, or when the engine is cold. The cold crowd will argue that when the engine is cold and at rest, all the oil is in the pan, and therefore the dipstick will give the most accurate reading. The hot crowd will argue that oil expands when hot, so the best time to check the oil is when the engine is warm.


Both crowds are right to a certain extent, and as long as the first two rules are adhered to everything should be fine. If your driveway at home is nice and flat, then check your oil in the morning when you grab the paper. If you live on a steep slope, then check your oil at the gas station when the engine is warm. Every other fill-up is a good schedule for oil checks.


Lastly there is the reading of the dipstick itself. Consult your owners or service manual for quantities, but as a general rule, add one quart of oil only if the oil is below the add mark. Never add oil if the level is between the two marks. Be careful to only pour oil into your engine where it belongs. Engine oil filler caps are usually clearly labeled with the word OIL and often include a pictogram of what looks like Aladdin's lamp—just like magic.