How to Check Your Oil
Check your car's oil level on the dipstick, read what the oil's color tells you, and top it off to the right mark without overfilling.
You will end up knowing where your dipstick is, how to read the level and the color of the oil, and how to top it off to the right mark without overfilling.
A regular check catches low oil before the engine runs short. Low oil means less of the film that keeps moving metal parts apart, which leads to friction, heat, and wear.
A clean rag or paper towel to wipe the dipstick. Keep one in the glove box or trunk so you always have it handy. If the level is low, you also need a quart of the oil your owner's manual specifies and a funnel.
Park on level ground and wait
Pull onto a flat surface and turn off the engine. Wait at least 5 minutes for the oil to drain back into the oil pan. If you check immediately after driving, part of the oil is still up in the engine and you will get a falsely low reading. Pull the hood release lever inside the car, usually low on the driver's side. Reach under the front edge of the hood, slide the safety latch, lift the hood, and secure it with the prop rod. After a drive, the engine and exhaust parts stay hot enough to burn, so touch only the dipstick handle and the filler cap.
Good to know: Checking in the morning before you start the car also works, because the oil has drained into the pan overnight. Mobil recommends checking either before starting the engine or 5 to 10 minutes after shutting it down, so that all the oil is in the pan when you measure it. Either timing gives a true reading.
Find the dipstick
Look for a brightly colored handle sticking up from the engine block. It is usually yellow or orange, shaped like a loop or T-handle. Where it sits depends on the engine, so it can be at the front, the side, or toward the back of the engine bay. If you cannot spot it, check your owner's manual. Some newer cars have electronic oil level sensors instead of a physical dipstick. If your car has one, your owner's manual names the dashboard or screen menu that shows the level.
Pull, wipe, and reinsert the dipstick
Pull the dipstick all the way out. It is a long, thin metal rod. Wipe it completely clean with your rag so you can get a fresh reading. Then push it all the way back into the tube until the handle seats fully. Pull it out again slowly and hold it horizontally. This second pull gives you the accurate oil level.
Read the oil level
Look at the tip of the dipstick. You will see two marks, dots, or lines. The lower mark means minimum and the upper mark means maximum. The oil film on the dipstick should sit between these two marks. Anywhere between them is a normal level. If it is near or below the lower mark, add oil until it reaches the upper mark (step 6), which is what Mazda's owner's manual tells owners to do.
Heads up: If there is no oil visible on the dipstick at all, do not drive the car. Running an engine with critically low oil can cause permanent damage. Add oil before you start the engine again.
Check the oil color and texture
While the dipstick is out, look at the oil itself. Fresh oil is amber and slightly transparent, but do not read too much into it turning dark. Motor oil contains detergents that hold dirt in suspension, so it darkens quickly in normal use, and color alone does not tell you it needs changing. Go by the mileage or time interval in your owner's manual. If the oil looks milky or has a frothy texture, that could indicate coolant mixing with the oil, which is a serious problem that needs a mechanic's attention. If you see metal flakes or grit, that also warrants a professional look.
Add oil if the level is low
Find the oil filler cap on top of the engine. It usually has an oil can icon on it. Use the viscosity grade printed on the cap or listed in your owner's manual. Common grades are 5W-30 and 0W-20. Unscrew the cap, set a funnel in the opening, and add oil in small amounts, about a quarter quart at a time. After each pour, wait a minute for the oil to settle, then recheck the dipstick. Stop when the level reaches the upper mark. Do not go past it, because overfilling can damage the engine (FAQ 3 below explains how). Replace the filler cap and close the hood.
If your oil is consistently low between changes, keep a quart in your trunk, top off as needed, and tell your mechanic at your next visit. An engine that keeps burning or leaking oil has a problem that is cheaper to fix early. When the oil is due for a change, our guide on how to change oil walks through doing it yourself.
Questions we get asked about this
Answers from experience, not a textbook.
Check it on the schedule in your owner's manual. Mazda's manual, for example, lists the engine oil level among the checks to make each time you refuel. If your manual gives no schedule, check it each time you refuel. Mobil notes that older vehicles tend to burn more oil, and that an engine's seals can wear over time and start to leak. It counts an engine with more than 75,000 miles as high mileage. Checking regularly helps you spot a leak or burning problem early, before it becomes an expensive repair.
Yes, once the engine has been off for 5 to 10 minutes. Mazda's manual has you warm the engine to normal operating temperature first, then switch it off and wait at least 5 minutes. What you cannot do is check it the moment you switch off, because part of the oil is still up in the engine instead of down in the pan. Warm oil does expand a little, so a hot reading can sit marginally higher than a cold one on the same engine. That only matters if you are watching a slow leak and comparing readings from week to week, in which case take them the same way each time and the comparison holds.
Overfilling can cause the oil to foam as the crankshaft churns through it. Foamy oil does not lubricate properly and can lead to overheating and engine damage. It can also increase pressure on gaskets and seals, causing leaks. If you accidentally overfill, a mechanic can drain the excess, or you can use an oil extractor pump to siphon some out through the dipstick tube.
Yes. Your engine is designed for a specific oil viscosity, like 5W-30 or 0W-20. Using the wrong grade can affect lubrication, fuel economy, and engine protection. The correct grade is printed on the oil filler cap and in your owner's manual. When topping off, match that viscosity and the certification your manual names, such as the API "Certified For Gasoline Engines" mark Mazda requires. Any brand that meets both will do, so there is no need to hunt down the exact bottle you used last time. Mobil says synthetic and conventional oils are generally compatible and unlikely to form a gel when mixed, but it advises against mixing as a habit, so top off with the same type you already run.
Car Owner Essentials
How to Check Tire Pressure
How to Change a Tire
How to Change Your Oil
How to Check Your Oil
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