Wondering whether your engine oil is still good? This guide walks you through signs to look out for, hands-on ways to check your oil, and what happens if you keep using it past its prime. Pick up smart tips to get the most life out of your oil, how to read your dipstick like a pro, and simple rules about when it's time to swap it out. Forget guesswork—use these pointers to make sure your engine stays in top shape.
