|“Oil doesn't just lubricate—it's the garbage disposal for the engine,” says mechanical and engine expert Mike Arman. “Oil gets contaminated with metallic particles from normal wear in the engine, and carbon and ash from burned oil.”
Then there are byproducts created by the water from exhaust. “It doesn't all go out the tailpipe,” Arman says. “Some goes down past the rings and into the oil. There, it combines with sulfur in the oil to make diluted sulfuric acid.”
As a product, motor oil is approximately 85 percent oil and 15 percent additives, such as detergent and anti-foaming stabilizers that break down over time due to these contaminants. That is why oil changes are necessary.
When do you need an oil change?
Every 3,000 miles is not the rule anymore. Vehicles are much more advanced now. The number may be 3,000, 5,000 or even 7,500 miles. You should change your oil as often as it's recommended in your owner's manual.
However, consider a shorter-than-normal interval if you have a long trip coming up.
In the end, it is about paying less—not more. It is human nature to try to stretch it but an oil change is around $50. An engine replacement is $3,000.
Stay prepared with your auto insurance. Nationwide offers special discounts for OSBA members. Learn more.