Checking Your Oil Level

A listener writes in with a pretty basic but important question:

Dr. Ron

Should I expect to get a different reading checking the oil hot or cold? I was told that the reading is closer to the add line if the engine is cold and closer to full if hot.

Thank You for response.

Dave

My reply as below...

Checking engine oil is one of the most basic, important steps in preventative car care yet next to tire pressure one of the most overlooked. Checking engine oil is best done on a cold engine or one that has been sitting for at least 30 minutes. Reason being this allows for oil that might be up in the cylinder head and intake area to drain back into the oil pan. While in most cases you would not or should not see the range change from the minimum line to maximum it does give you the most accurate reading. Typically the middle of the high and low marks is where you want to be for level. This allows and compensates for changes in pan level due to temperature, consumption (if any) and external seepage. In most cases the greater majority of vehicles on the road today should not and do not need oil added in between changes (assuming the 3-4 month rule/3,000 mile interval). The industry in recent years has mellowed some and tolerates a quart every 1,000 miles as OK. I do not and disagree with this figure.

Thanks for writing in, please don't forget to tune into the show every week. Remember, while it varies by market place you can reach me in the studio Sundays 10-Noon EST at 1/800-544-7070 to ask questions such as this and anything else about your car and truck.

Ron