I Tested GL-4 80W-90 Gear Oil: My Honest Review of Performance, Protection, and Smooth Shifting
When I think about the components that keep a vehicle running smoothly, gear oil is one of those unsung essentials that often gets overlooked until something starts to feel off. In particular, GL-4 80W-90 gear oil plays an important role in protecting gears, reducing friction, and helping transmissions and differentials perform reliably under pressure. Whether…
