Agree with JD. Back in the day, it was common knowledge that if your "idiot" light came on it was generally too late. If you knew anything about engines at all, you knew enough not to wait until the "idiot" light came on to check your
oil level, Even regular factory gauges in older american cars were never very accurate. We even believed that many
oil and temp gauges were designed to stay in the middle regardless of what was really going on in the engine.