What happens when you change your engine oil
Changing your engine oil means draining the old oil from your engine, replacing the oil filter, and filling the engine with fresh oil. Old oil breaks down over time and loses its ability to protect your engine's moving parts. Fresh oil reduces friction, carries away dirt and heat, and keeps your engine running longer.
Most cars need an oil change every 3,000 to 10,000 miles, depending on your vehicle's age, the type of oil you use, and your driving habits. Newer cars with synthetic oil can often go longer between changes than older cars with conventional oil. Check your owner's manual for the exact interval your car needs.
Key Takeaways
- You will need an oil drain pan, a wrench to remove the drain plug, an oil filter wrench, and the correct type and amount of oil for your car.
- The entire process takes 30 minutes to an hour once you have the right tools and know where the drain plug and filter are located.
- Your owner's manual tells you the exact oil type, viscosity grade, and capacity your engine needs — using the wrong oil can damage your engine.
- Warm oil drains faster than cold oil, so running your engine for a few minutes before you start makes the job easier.
- Dispose of old oil at a recycling center, auto parts store, or service station — never pour it down a drain or into the ground.
Gather your tools and materials before you start
You need an oil drain pan (a shallow metal or plastic container), a wrench that fits your drain plug, an oil filter wrench (a metal band or socket that grips the filter), fresh oil in the correct type and amount, and a new oil filter. You will also want ramps or jack stands to safely lift the front of your car, old towels or rags, and a flashlight if you are working in dim light.
Find your car's oil capacity and the correct oil type in your owner's manual — this is the most important step. The manual will list the viscosity grade (like 5W-30 or 10W-40) and whether your engine needs conventional, synthetic blend, or full synthetic oil. Using the wrong oil can reduce engine protection or cause damage. If you cannot find your manual, search online for "[your car year, make, model] oil type" or ask at an auto parts store.
Locate the drain plug and oil filter under your car
Raise the front of your car safely using ramps or jack stands — never work under a car supported only by a jack. Once the car is elevated, look underneath toward the front of the engine for a bolt sticking out of the oil pan, usually near the bottom. This is your drain plug. The oil filter is a cylindrical canister about the size of a soda can, typically mounted on the side of the engine.
If you cannot find either part, consult your owner's manual or search for a diagram online. Knowing where these parts are before you start saves time and frustration. Take a photo with your phone so you can reference it while you work.
Drain the old oil from your engine
Position your oil drain pan directly under the drain plug. Using your wrench, turn the plug counterclockwise to loosen it, then unscrew it by hand once it is loose enough to grip. Oil will flow out — this is normal and expected. Let the oil drain completely into the pan; this takes 5 to 10 minutes. Once the flow slows to a drip, wipe the drain plug clean with a rag and screw it back in by hand, then tighten it with your wrench. Do not overtighten — hand-tight plus a quarter turn is usually correct.
Warm oil drains much faster than cold oil, so if your engine is cold, you can run it for a few minutes before you start draining. This makes the job quicker and ensures more old oil leaves the engine. Be careful — the oil and engine parts will be hot.
Remove the old oil filter and install a new one
Position your drain pan under the oil filter to catch any oil that spills when you remove it. Use your oil filter wrench to loosen the filter by turning it counterclockwise. Once it is loose, unscrew it by hand and set it aside in your drain pan. Wipe the filter mounting surface on the engine clean with a rag.
Take your new oil filter and explore a thin layer of fresh oil to the rubber gasket (the ring around the top of the filter). This helps create a good seal. Screw the new filter on by hand until the gasket touches the engine, then turn it an additional three-quarter turn. Hand-tight is correct — do not use the wrench to tighten it further.
Fill your engine with fresh oil and check the level
Locate the oil filler cap on top of your engine — it usually has an oil can symbol on it. Unscrew the cap and set it aside. Pour in the amount of oil your manual specifies, usually between 4 and 6 quarts. Pour slowly and stop halfway through to check the level with your dipstick.
Pull out the dipstick, wipe it clean on a rag, reinsert it fully, then pull it out again to read the level. The oil should reach the "full" mark. If it is below the mark, add more oil a little at a time until it reaches full. Overfilling your engine can cause damage, so be careful not to add too much. Once the level is correct, screw the oil filler cap back on.
Start your engine and check for leaks
Start your car and let it run for 30 seconds to a minute. This circulates the new oil through the engine and helps the new filter fill with oil. Turn off the engine and wait a few minutes for the oil to settle, then check the dipstick again to confirm the level is still at the full mark. Look under the car for any leaks around the drain plug or filter — a few small drips are normal, but steady leaking means something is not tight enough.
If you see a leak, turn off the engine, let it cool slightly, and tighten the drain plug or filter a bit more. Once everything looks dry, lower your car back to the ground and dispose of your old oil at a recycling center, auto parts store, or service station. Many auto parts stores will take old oil for free.
Frequently Asked Questions
How do I know if my car needs an oil change?
Check your owner's manual for the recommended interval — usually every 3,000 to 10,000 miles depending on your car's age and oil type. Some cars have an oil change reminder light on the dashboard that tells you when it is time. You can also check the dipstick: if the oil looks dark or dirty, an oil change is due.
What should I do with the old oil?
Never pour old oil down a drain, into the ground, or in the trash. Take it to a recycling center, auto parts store, or service station — most accept used oil for free. Some will even take the old filter. Call ahead to confirm they accept oil before you go.
Can I change my oil if the engine is cold?
Yes, but it will take longer because cold oil drains slowly. Warming the engine for a few minutes before you start makes the job faster and ensures more old oil drains out. Let the engine cool for a few minutes after running it so you do not burn yourself on hot parts.
What if I spill oil on my driveway?
Cover the spill with cat litter, sand, or an absorbent material and let it sit for several hours to soak up the oil. Sweep it up and dispose of it as hazardous waste. For large spills, contact your local environmental agency for guidance on cleanup.
Do I need to reset anything after changing the oil?
Some cars have an oil change reminder light that you need to reset manually. Check your owner's manual for the steps — it usually involves holding down a button on the dashboard or using the car's menu system. If your car does not have a reminder light, you do not need to reset anything.