So, I know that hardly anyone does this anymore, but you really should pull the dipstick and check the oil level at every fill up.
The “oil life monitor” which is the % oil life sensor in the instrument cluster only tells you the computer calculated life remaining in the oil. It’s based on a ton of research by engineers at GM, and algorithmically counts down from 100% based on the number of engine revolutions, with some de-rating for engine temperature, number of cold starts, driving conditions, etc. It has shown to be pretty accurate by used oil analysis performed by many.
But, that piece of tech assumes you start with a full crankcase of fresh oil when reset to 100%, and that you keep the crankcase properly filled with oil. The best way to do this is following the oil check procedure in the owners manual. Basically: pull the dipstick occasionally and check.
In every vehicle I’ve ever owned, I check it the day I buy it, then at every fill up, and after every oil change. I’ve had a couple of my vehicles overfilled or under filled by the service tech..and corrected on the spot. Checking at every fill up gives you:
- Confidence you are not low on oil
- Indication of how your specific engine is behaving
- And over time, if you know you consume 0.5qt every 5000 miles, also an indication when something is changing, if all of a sudden it’s 1qt every 2500
TLDR: don’t be a dipstick, use the dipstick!