Separating Facts from Fiction: Motor Oil

Unless you’re a totally irresponsible driver, you already know that your car engine needs motor oil to work properly and smoothly. The best motor oil keeps the moving parts lubricated to minimize the friction, it protects against corrosion, and it can even help keep the motor free of gunk and sludge.

Now you’ve heard about FAQs, right? Here are some questions that are less frequently asked, and that’s because so many people think they already know the answer.

Do Synthetic Oils Cause Oil Leaks?

For many the belief that synthetic oils cause oil leaks has been passed down through generations of car mechanics ever since the 1970s. That was the era when the first synthetic oils were offered as an alternative to petroleum-based motor oils. Unfortunately, those first chemical-based products weren’t exactly gentle with the engine seals and gaskets. The synthetic oils then caused these seals and gaskets to shrink a little, and that caused messy leaks.

But a funny thing about science is that scientists tend to work to correct such problems. So nowadays the modern formulation of synthetic motor oils doesn’t cause this shrinkage. In fact, synthetics are considered as superior by many.

There may be a certain truth to this belief, however – if you’re driving a 15-year old car. A synthetic may be too effective in cleaning off sludge, and those bits of sludge may actually be sealing off small cracks in the seals. So when the bits of sludge are removed, the leaks that have always been there may cause problems.

Is It Time to Change the Motor Oil When Its Color is Dark?

We can already hear the “YES” replies to this question from many drivers. We can even imagine the smirk accompanying the reply. Isn’t it obvious, they’ll ask. When the oil was fresh and new, the color was light amber. Now that it has turned dark, it’s time for a change. Right?

Wrong. Motor oil isn’t bath tub water. If the water in your tub turns cloudy, then yes you really need to change the water. But motor oil is different. It has detergent properties, which means it is dispersing the particles that can result in sludge. These particles are held in the oil itself, so it looks dirty. So when you see the oil turning muddy or dark, it only means it is doing its job. It doesn’t necessarily mean its job is done.

However, there’s a limit as to how much of these particles can be suspended by the oil. When the oil is saturated with these particles, an oil change is necessary.

Do You Have to Change Oil Every 3,000 Miles?

A lot of people think this is true, and that’s because there was a time when virtually every car maker recommended this limit in their manuals. But today even these car makers have admitted that oil changes don’t need to be that frequent. You should still follow your car manufacturer’s recommendations regarding oil changes, but chances are it’s not going to be every 3000 miles.