What Type of Oil Should Be Added to a Gasoline Generator?

[Ronnie]

Gasoline generators generally use 15W-40 or 5W-30 engine oil. Below are the specific functions of engine oil: 1. Shock absorption and cushioning: When the pressure in the engine cylinder rises sharply, it suddenly increases the load on the piston, piston rings, connecting rod, and crankshaft bearings. This load is transmitted and lubricated through the bearings, providing a cushioning effect against the impact load. 2. Rust and corrosion prevention: The lubricating oil adheres to the surface of parts, preventing contact with water, air, acidic substances, and harmful gases. 3. Lubrication and wear reduction: There is rapid relative sliding between the piston and cylinder, as well as between the main shaft and bearing shells. To prevent excessive wear, an oil film must be established between the two sliding surfaces. A sufficiently thick oil film separates the surfaces of the relatively sliding parts, thereby reducing wear. 4. Cooling: The engine oil carries heat back to the oil tank and dissipates it into the air, helping the radiator cool the engine.

[MacJosiah]

I've worked with quite a few gasoline generators, and most recommend SAE 10W-30 oil. This viscosity is suitable for year-round climates and is less likely to cause issues due to temperature changes. In the summer when temperatures are high, I sometimes use 10W-40 for added protection, then switch back to 10W-30 in winter to prevent thickening. The key is to check the generator's manual, as requirements vary slightly by brand. Using the wrong oil can lead to faster engine wear or smoking. I believe it's essential to check the oil level and replace it every 50 hours of use—don't wait until a problem arises. When choosing a brand, you don’t need expensive products; reputable oils from major manufacturers like Mobil or Shell are perfectly safe. Darkening oil is a clear signal it’s time for a change—don’t let small issues turn into big ones and disrupt your plans. Maintaining this habit really helps extend the machine’s lifespan hassle-free.