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How Should I Select the Right Engine Oil for Huntsville Generators?

Generator repair in Alabama

Engine motor oil helps by lubricating the inner components of the engine. The oil protects the engine parts against accelerated wear and tear. It prevents rust formation inside and keeps the engine cool during operations.

You need to buy the right engine oil for your generator to ensure effective performance. The best engine oil depends on the weather conditions. Here are some tips for selecting the right engine oil for Huntsville generators.

1. Know the Engine Type

Generators come with a 2- or 4-stroke engine. Each of these generators requires a different type of engine oil. For a 2-stroke engine, you can add a mixture of fuel and engine oil. On the other hand, the fuel and oil are used separately for a 4-stroke engine.

Read the generator manual to find out what type of oil you can use for the generator. A mixture of fuel and oil is generally cheaper as compared to generators that require separate fluids for operation and lubrication.

2. Oil Viscosity

The viscosity of the engine oil is another important consideration. The viscosity of the oil is specified by the SAE label. SAE refers to the Society of Automotive Engineers who came up with the grading of the engine oil. Purchasing the engine oil with the right viscosity is important otherwise it can wear out the generator.

SAE label consists of two numbers. The first number next to W is the ‘winter grade’ of the engine oil that refers to the viscosity at a colder temperature that ranges between 230F to -40 0F (-50C and -400C). A lower W grade oil performs well at a lower temperature. If you live in an area where winter temperature rarely goes below 230F, you should consider using generator oil with grade 25W. A lower grade is recommended if the temperature gets too cold during the winter.

The other SAE number refers to the viscosity grade at 2120F (1000C) that is considered the approximate operating temperature of the engine. The non-winter grade viscosity is calculated by timing the flow of oil at the operating temperature. A higher non-winter grade means that the oil is less viscous and takes longer to flow.

Most generators require an engine oil with a grading of SAE 10W-30. The engine oil will perform best at a temperature up to -40F (-200C). However, you must read the generator instruction manual to know more about the correct type of engine oil.

3. Diesel Oil Grades

Diesel engine oils have specific grading that determines the suitability of the fluid for specific weather conditions. The table shows the specific diesel engine oil grade suitable for different temperatures.

Diesel Grading Suitable Temperature
0 39.20F (40C)
-10 230F (-50C)
-20 230F to 6.80F (-50C to -140C)
-35 6.80F to -20.20F (-140C to -290C)
-50 -20.20F to -47.20F (-290C to -440C)


An important point to note is that different diesel oil can be blended. As a result, you don’t need to change the diesel grade for specific weather. You can add kerosene to make a diesel oil suitable for lower temperatures.

The right engine oil will ensure optimum lubrication and temperature control. It will also prevent deposits from forming inside the engine. You must read the instruction manual to know about the right type of generator.

Regular maintenance of the generator is also important to ensure proper generator operations. Contact Generac Superstore for generator maintenance in Huntsville and Birmingham Alabama and Nashville Tennessee. We offer generator services in Alabama and Tennessee for residential and industrial generators.


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