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How to Do an Engine Oil Analysis


Interpreting Oil Analysis Results
You can buy an oil analysis kit that lets you interpret the results for yourself, or you can purchase the services of a professional laboratory that will analyze the results for you.
You can buy an oil analysis kit that lets you interpret the results for yourself, or you can purchase the services of a professional laboratory that will analyze the results for you.
Monty Rakusen/Getty Images

So just what, exactly, will all this information about your engine's oil tell you? And what will that do for you?

If you send your oil sample to a lab for analysis, technicians will check for lots of things, including the presence of metals and other elements, such as aluminum, chromium, iron, copper, lead, calcium and more. If certain materials are abnormally high in your oil, it could point to excessive wear in a certain engine part.

The analysis also lets you know the oil's viscosity, compared to what it should be. The Total Base Number (TBN), which lets you know how much of the additives -- chemicals that enhance the oil's effectiveness -- remain.

Having this knowledge beforehand could save you lots of money and aggravation, as it gives you time to catch problems before they result in a catastrophic failure on your vehicle (like an engine seizing up).

The results also let you know if the oil is excessively contaminated with fuel, water or antifreeze, all of which reduce the oil's ability to lubricate your engine effectively.

But there are at least two more ways an engine oil analysis can save you money.

If you're considering buying a used vehicle, a car, a truck, a motorcycle or even a piece of diesel construction equipment can be quickly given the oil analysis test to see what kind of shape they're really in, beneath their flawlessly washed and waxed exteriors. An engine oil analysis can give you a look deep inside the workings of the engine without you having to take it apart. Naturally, a lab report that comes back showing lots of metal particles may be a sign that you should avoid taking that vehicle home.

Another potential money saver is if the analysis shows you can extend the interval between your oil changes. The recommendation used to be that you change your oil every 3,000 miles (4,828 kilometers), no exceptions, if you wanted your car to last. But on modern vehicles, the interval between changes can be 10,000 miles (16,093 kilometers) or even longer. That represents big savings of time and money, not to mention giving a break to the environment by not having to produce and then dispose of those additional quarts of oil.

For more information about engine oil analysis, be sure to follow the links on the next page.


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