Oil Change

Dear Tom & Ray,

I would like you to confirm whether this is an ?old wives tale?.

Will I get a better oil change when the oil is hot rather than cold, the thinking being that driving the car has ?stirred up? any contaminants in the oil and so more contaminants will drain out with the oil?

And if this is so, what would you consider enough driving distance to get the oil hot on a cold day in January or a hot day in August?


Columbus, OH

No T&R here…but warm is better, not because it stirs up stuff (that would be trapped in the filter, anyway) but because warm oil drains faster, so you get more old oil out. As for how far, 13.5 miles in January, 3.6 miles in August…or until you get warm air out of the heater :wink:

Run it up to full normal operating temperature then change. Be careful not to burn yourself.

I always change my oil when the engine is at normal operating temperature. The oil and the filter will be hot, so be careful.

I agree with all the replies about the benefits about changing the oil when the oil temperature is warm.

However, if you change the oil when the owners manual says you should, you’ll never see any difference in engine life whether the oil was changed when hot or cold.

In theory your thinking is valid. However, I often do mine first thing in the morning in spring, summer, and fall and have never worn an engine out even after hundreds of thousands of miles. In winter I warm it up first.

The important thing is that you maintain and don’t abuse the car. I’ve yet to see any evidence that changing it either hot or cold has any effect on engine wear.

Very true, but I find it easier and faster to change if the oil is at least warm.

My Sienna has a horizontal filter, which means oil spills out if the filter is full. I change it in the morning before I start it to minimize spilling. First, I change the filter and clean up any dripped oil, then I open the drain plug and go in and surf the web for a while. Being retired, I am in no rush.

When we used to park the car and take the bus into Mexico, I’d change it before starting it, which meant not a drop got spilled.

I also change mine after the car has sat overnight. ALL the oil has drained down, there is nothing to “stir up”, no danger of burns or hot oil spilling all over…Of course, I don’t live in Minnesota…Modern 5W-20 oil drains pretty fast regardless of temperature…