I Tested SAE 75W-90 GL-5: What GL-5 Means and Why It Matters
If I’ve ever stared at a bottle of gear oil and wondered what all those numbers and letters actually mean, I’m not alone. One label that often raises questions is SAE 75W-90 GL-5, especially the part that says GL-5. At first glance, it can look like technical jargon meant only for mechanics, but it actually…
