Should I change my oil when it’s recommended?
In general, yes. Changing your vehicle’s oil is one of the most important things you can do to avoid bringing large bags of money to your mechanic later on.
However, there’s a lot of controversy about exactly when engine oil gets old and how often it should be replaced with new oil. Because there are many factors at work — how you drive, the condition and age of the engine, the external environment you drive in, and stop-and-go versus highway driving — it’s an inexact science. Owner’s manual recommendations for oil and filter changes vary from 3,000 to 10,000 miles.
We recommend that you change your oil and filter every 5,000 miles. That’s our best estimate. It may be too soon for many people and too late for a few, but for the vast majority, 5,000-mile oil changes will help your engine last to a ripe, old age.
Why do I have to do this?
Oil undergoes thermal breakdown due to high operating temperature. When this occurs, the oil becomes less effective as a lubricant. And without a good lubricant (read: expensive), parts of the engine rub together and wear each other out.
Oil also contains additives that have the ability to neutralize acids. Over time, these additives get used up and stop being effective.
Finally, oil can absorb water, dust and combustion byproducts and also hold them in suspension. Eventually, the oil gets saturated with this stuff and can’t absorb any more. Then that stuff remains in the engine and can cause corrosion.
What happens if I don’t do this?
Your engine won’t last as long as it could. Oil serves many crucial functions, and clean oil performs those functions better than dirty oil. Oil is relatively cheap, and changing your oil every 5,000 miles is a very cheap insurance policy against major repairs down the road.