How often should I check my oil?

Monthly, and before any long road trip. If your engine is older, burns oil, or has a known leak, check weekly — some engines consume a quart every 1,000–2,000 miles, and running two quarts low does real bearing damage.

What oil should I buy to top off?

The viscosity printed on the filler cap or in the owner's manual — commonly 5W-30 or 0W-20 on modern cars. The API or ILSAC specification on the bottle matters more than the brand; any oil meeting the spec is fine.

What does the oil color tell me?

Amber to light brown is healthy. Very dark means a change is due soon. Milky or tan foam means coolant is mixing into the oil — usually a head-gasket problem — so stop driving and get it checked.

What if the level is way over MAX?

Do not drive far. An overfilled crankcase whips the oil into foam, which starves bearings and can blow out seals. Drain the excess through the drain plug or have a shop do it — a fluid extractor down the dipstick tube also works on many cars.

How to Check Your Engine Oil

About 5 minutesEasy7 steps

Low oil kills more engines than any other neglected fluid, and checking it takes five minutes with nothing more than a paper towel. The dipstick only reads true when the car is level and the oil has drained back into the pan. Check monthly and you will catch leaks and oil consumption long before the warning light does.

Checking oil is low-risk, but keep hands, hair, and clothing clear of belts and fans if the engine ran recently, and watch for hot surfaces. If the oil looks milky or foamy, or the level keeps dropping between checks, have a shop diagnose it before you drive further.