You’ve probably heard it before: “Oil is the lifeblood of your machine.”It’s not just a catchy saying—it’s literal truth. For an excavator, oil testing isn’t some optional extra you do when you’ve got time. It’s an essential diagnostic tool that tells you what’s going on inside the machine long before you hear the first grind, smell the first burn, or see the first warning light. Skipping oil testing is like ignoring your own blood test results because “you feel fine.” The re