20-50 Vs. 10-30 Motor Oil

by Adam Smith
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Choosing the proper motor oil is a necessity. Cars rely on this lubricant to prevent damage and to improve the efficiency and life of the engine. There are many different types of oils that have specific applications for use in lawnmowers, cars and boat engines. 20-50 and 10-30 are two oils that are designed for use in vehicles but are quite different from each other.

Purpose of Motor Oil

Motor oil provides lubrication to the internal parts of an engine while preventing corrosion and cleaning and cooling the engine. If an engine was to run without this liquid, it would seize up and be irreparably damaged. Each car engine requires a specific volume of oil to be added and changed at specific intervals. Many older cars require oil changes at 3,000 miles while some newer cars may last up to 10,000 miles between oil changes.


Viscosity is a term that refers to the thickness or thinness of a motor oil. The viscosity of oil is a two-number system that indicates the thickness of oil at a very low temperature and at the normal operating temperature of the engine. The letter "W" in the viscosity of an oil means it is a winter grade oil.

Viscosity Differences

Lower viscosity oils are preferable in cold areas. These oils are thinner and flow easier in extremely cold temperatures. A car using a high viscosity oil during extremely cold weather may have trouble starting up. Conversely, higher viscosity oils are preferable for very warm areas. These thicker oils can improve the performance of a car in hot temperatures.

20-50 Oil

20-50 oil is an extremely viscous oil. This oil is suitable for hot climates and will provide more protection in hot weather than 10-30 oil will. 20-50 oil is also a good choice for some older vehicles. Since 20-50 oil is very thick, it may help prevent engine leaks in old cars. It is important to note that 20-50 oil may be too thick for many engines and can cause serious damage.

10-30 Oil

10-30 oil isn't the thinnest oil on the market, but is much thinner than 20-50. This oil is used in average temperature ranges and is suitable for applications above -20 degrees Fahrenheit. Some people may switch to 10-30 after their vehicles have about 100,000 miles because it may offer more protection and better lubrication. More cars use 10-30 oil than 20-50 oil.

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