How Often To Change The Oil 

  Let’s look at how and where you drive. These things have a great effect on how often you change your oil.

1.   Do you live in a climate were the temperature stays basically the same or does it vary during the year; it warm in the summer months and cold during the winter months?

• Temperature has a great effect on the engine oil. During cold weather water condenses inside the engine block in the form of ice. Just like the windshield of you car. As the engine warms up the ice melts and the water go into your oil. Cold starting of the engine requires more gasoline. Cold gas is hard to vaporize and liquid gas will not burn. Most of the unburned gas goes out the exhaust but some of it goes down the cylinder walls of you engine and into the oil.

2.      Do you always drive on paved road or do you sometimes drive on dirt road; do you live in the city or the country?

• The ideal air/fuel ratio under most operating conditions is approximately 14.7 pounds of air mixed with one pound of air (14.7:1).  The air we bring in comes from the outside of the engine. Along with it comes dirt from the outside.  Even though we filter out most of the dirt out, some still gets into the engine and into the engine oil.  If you drive on dirt roads you will need to change your oil more often than if you drive only on paved roads.

3.      Do you do mostly long distance driving (over 15 miles) or short distance driving (under 15 miles)?

• In order to rid the oil of the liquid gasoline and water you must completely warm you engine up. The heat from the engine causes the liquid gasoline and the water to evaporate.  The gasoline and water vapor are then removed from the engine through the crankcase ventilation system.  In the winter this takes about 15 miles of driving. If you only do short trip driving you never get rid of all the gasoline and water. This dilutes the oil and prevents the oil from doing its job properly.

• Actually the more you drive the less often you need to change your oil and the people who short trip driving winter driving should change there oil more often.

When determining how often to change your oil, my recommendation is to use (after considering the above) what ever method works best for you and do it on a regular schedule.

In the owners manual for you car you can find the manufactures recommendations for changing oil or, you can develop you own.  I personally feel the manufactures recommendation is not often enough. Many people and the manufacture base oil changing on number of miles.  Some people use 2000 miles some 3000 miles and so on.  Manufactures, because of improvements in engine oils, are recommending up to 7500 miles. 

I personally change my oil based on time not miles.  I change the oil in my vehicles every 90 day or 3 months regardless of the number of miles I travel. This takes into consideration all kinds of driving conditions and it’s easy to remember. And remember, change your oil filter every time you change your oil.

Changing the oil in your vehicles engine and replacing the oil filter will extent its life and save you money.

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