![The Difference Between GL-4 and GL-5 Gear Oil](https://blog.amsoil.com/wp-content/uploads/2022/05/Diesel_Dually_Pickup_1200x675.gif)
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The Difference Between GL-4 and GL-5 Gear Oil
The main difference between GL-4 and GL-5 gear oils is in the level of extreme-pressure (EP) additives.
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