What happens when you change your oil
Changing your oil means draining the old oil from your engine, replacing the oil filter, and filling the engine with fresh oil. The whole job takes 30 minutes to an hour if you have the right tools and know where everything is. You'll need your car's make, model, and year to find the correct oil type and filter, because different engines hold different amounts and use different weights of oil.
The reason you do this is that oil breaks down over time and collects dirt and metal particles from the engine. Fresh oil protects your engine better and helps it run cooler. Most cars need an oil change every 5,000 to 7,500 miles, though some newer vehicles can go 10,000 miles or longer — check your owner's manual for your specific interval.
Key Takeaways
- You will need your car's year, make, and model to buy the correct oil type and filter size before you start.
- The job requires an oil drain pan, a wrench to remove the drain plug, an oil filter wrench, and a way to safely raise the car or access the underside.
- Drain the old oil while the engine is warm but not hot, then replace the filter and add new oil to the level shown on your dipstick.
- Running the engine for a minute after filling lets the new oil circulate, and you should check the level again after a few minutes of sitting.
Gather your tools and materials before you start
You need an oil drain pan (a shallow metal or plastic container to catch old oil), an oil filter wrench (a socket-shaped tool that grips the round filter), a regular wrench or socket set to remove the drain plug, and new oil in the weight and quantity your car needs. You also need a way to safely get under the car — either a jack and jack stands, a set of ramps, or access to a lift if you're working at a shop.
Buy the oil and filter at an auto parts store. Bring your car's year, make, model, and current mileage, and the staff will hand you the correct items. If you're unsure about the oil weight, check your owner's manual or look inside the driver's door jamb, where a sticker often lists the recommended oil type. Keep old rags or paper towels nearby to wipe your hands and catch spills.
Warm the engine and raise the car safely
Start the engine and let it run for two or three minutes so the oil warms up. Warm oil flows faster and drains more completely than cold oil. Then turn off the engine and wait a minute — you want the oil warm enough to drain quickly, but not so hot that it burns your skin.
Raise the car using a jack, and place jack stands under the frame on both sides for safety. Never work under a car supported only by a jack. If you're using ramps, drive the front wheels slowly up onto them and set the parking brake. Make sure the car is level and stable before you slide underneath.
Drain the old oil and replace the filter
Locate the oil drain plug on the bottom of the engine — it's a bolt sticking down from the oil pan. Position your drain pan underneath it, then use your wrench to turn the plug counterclockwise. Once it's loose enough, unscrew it by hand and let it fall into the pan. Oil will pour out; let it drain completely, which takes five to ten minutes.
While the oil drains, find the oil filter, which is a cylindrical canister usually on the side of the engine. Use your oil filter wrench to turn it counterclockwise until it comes free, then unscrew it by hand. Wipe the rubber gasket (the flat ring on top of the filter) off the engine with a rag. Screw the new filter on by hand until the gasket touches the engine, then turn it another three-quarter turn — do not use the wrench to tighten it.
Reinstall the drain plug and add new oil
Wipe the drain plug clean with a rag and screw it back into the oil pan by hand. Once it's snug, use your wrench to tighten it — firm pressure is enough; over-tightening can strip the threads. Lower the car back to the ground using the jack or by backing off the ramps.
Open the hood and locate the oil filler cap on top of the engine — it usually has an oil can symbol on it. Unscrew the cap and set it aside. Place a funnel in the opening and slowly pour in the new oil. Your owner's manual tells you how much to add; most cars hold between four and six quarts. Pour in most of it, then stop and check the level.
Check the oil level and run the engine
Pull out the dipstick, a long thin rod with markings on it that shows the oil level. Wipe it clean with a rag, reinsert it all the way, then pull it out again and read where the oil reaches. It should be between the minimum and maximum marks. If it's low, add a little more oil and check again. If it's overfull, you've added too much — you'll need to drain some out or take the car to a shop to have excess removed.
Screw the oil filler cap back on. Start the engine and let it run for about a minute so the new oil circulates through the engine and the new filter fills. You'll see the oil pressure light on your dashboard go out once the oil reaches the filter. Turn off the engine and wait five minutes, then check the dipstick one more time to make sure the level is still correct.
Dispose of old oil properly
Old oil cannot go in the trash or down the drain — it contaminates soil and water. Most auto parts stores that sell oil will take used oil for free, even if you didn't buy it from them. Pour your old oil into a clean container with a lid, load it in your car, and bring it to the store. Some recycling centers also accept used oil, and some municipalities have hazardous waste collection days.
Keep your receipt or note the date and mileage when you changed the oil. This helps you remember when the next change is due and provides a record if you ever need to show proof of maintenance for warranty or resale purposes.
Frequently Asked Questions
What if I can't get the oil filter off?
The filter may be on too tight or stuck. Tap the wrench gently with a hammer to get a better grip, or wrap a rubber band around the filter to improve traction. If it still won't budge, you may need to visit a shop — forcing it can damage the engine.
Can I change my oil if the engine is cold?
Yes, but warm oil drains faster and more completely. If you must work on a cold engine, let it run for a few minutes first. Never work on a hot engine right after driving — wait at least 10 minutes so it cools enough to touch safely.
How do I know if I've added too much oil?
Too much oil can damage the engine by creating pressure and foaming. If the dipstick reads above the maximum line, you've overfilled. You'll need to drain the excess or have a shop remove it. Do not drive the car until the level is correct.
What should I do with the old oil filter?
Some auto parts stores take used filters for recycling. Call ahead to ask, or drain the oil from the filter into your collection container and recycle the filter as scrap metal at a local recycling center.
Do I need to reset anything after changing the oil?
Some newer cars have an oil change reminder light on the dashboard. Check your owner's manual for how to reset it — the process varies by make and model. Older cars do not have this feature.