I disagree, you should run a stored car’s engine

June 1, 2010 | By Richard Prince


Why do you insist on telling people “the best thing you can do for a car in storage is to run the engine on a regular schedule?” One of the byproducts of combustion is sulfuric acid. This product of combustion slips by the rings and works its way into the oil. Unless the oil is brought up to around 200-degrees (the boiling point), it will stay in there and cause corrosion. You can’t get the oil up high enough in temperature to boil it out by just running the engine. It must be under load. This is bad advice. Sulfuric acid will eat holes in concrete, let alone metal. I don’t know the answer but your answer is not correct.


I thank you for taking the time to share your thoughts but for several reasons I couldn’t disagree with you more. Corrosive compounds are a natural consequence of the combustion of fossil fuels and thus running an engine while a vehicle is in storage—or on the road in daily use—will generate acids and other harmful substances. Elevated temperature over a sufficient duration of time will reduce the impact some of these harmful substances have on the engine’s parts, but this does not apply to sulfuric acid. The boiling point of sulfuric acid is, in fact, approximately 620 degrees F and your engine will fail long before its coolant or oil reaches this temperature.

The primary way in which the harmful effects of combustion’s corrosive byproducts are offset is by blending additives into engine oil. These additives are consumable and this is one of the reasons why oil should be changed on schedule. Regularly running the engine of a car in storage helps keep its parts lubricated and moving freely.

If possible, driving the vehicle a little bit, even just up and down the driveway, will also help a great deal because this facilitates the circulation of lubricating fluid in the transmission and differential, and it helps the brakes, steering and other moving parts stay free.

When running a car that’s in storage, the engine should be brought up to regular operating temperature and then run at least 20 minutes more. If necessary, you can block part of your radiator with a piece of cardboard in order to restrict airflow and bring the temperature up to where it should be.