What happens when you change your oil

An oil change means draining the old oil from your engine, replacing the oil filter, and filling the engine with fresh oil. The job takes 30 minutes to an hour if you have never done it before. You will need a wrench, an oil filter wrench, a drain pan, and new oil — the type and amount depend on your specific car model.

Oil breaks down over time and collects dirt and metal particles from engine wear. Fresh oil lubricates moving parts, reduces friction, and helps your engine run cooler. Most cars need an oil change every 3,000 to 10,000 miles, depending on the oil type and your vehicle's age. Check your owner's manual for the exact interval for your car.

Key Takeaways

  • You will need the correct oil type and amount for your car, which you can find in the owner's manual or on a sticker under the hood.
  • Drain the old oil while the engine is warm but not hot, then replace the oil filter before adding new oil.
  • Check the oil level with the dipstick after the engine has cooled for a few minutes to make sure you added the right amount.
  • 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 materials before you start

Before you begin, park on a level surface and let the engine cool for at least five minutes. Warm oil drains faster than cold oil, but hot oil can burn your skin. Collect these items: a socket wrench or adjustable wrench that fits your drain plug, an oil filter wrench, a drain pan large enough to hold all the old oil, new oil in the correct type and amount, a new oil filter, and rags or paper towels.

Find the oil type and capacity in your owner's manual or on a sticker inside the driver's door jamb. Common types are 5W-30, 10W-30, and 0W-20 — the numbers refer to how the oil flows at different temperatures. If you are unsure, ask at an auto parts store with your vehicle's year, make, and model. Most cars hold between 4 and 6 quarts of oil.

Drain the old oil from underneath

Locate the drain plug on the underside of the engine — it is a bolt sticking down from the oil pan. Position your drain pan directly underneath it. Use your wrench to turn the plug counterclockwise until it is loose enough to unscrew by hand. Finish unscrewing it slowly so the oil drains into the pan rather than onto the ground. Let the oil drain completely, which takes five to ten minutes.

Once the dripping slows to a few drops, wipe the drain plug clean with a rag and screw it back in by hand until it is snug. Do not overtighten it — hand-tight is enough. If your drain plug has a rubber washer, replace it with a new one to prevent leaks. Some plugs have a metal crush washer that should also be replaced each time.

Remove and replace the oil filter

The oil filter is a cylindrical canister usually located on the side of the engine. Position your drain pan underneath it to catch any remaining oil. Use an oil filter wrench to turn the filter counterclockwise until it is loose, then unscrew it by hand the rest of the way. Dispose of the old filter in your drain pan or a separate container.

Before installing the new filter, wipe the rubber sealing surface on the engine with a clean rag. Apply a thin layer of new oil to the rubber gasket on the new filter — this helps create a watertight seal. Screw the new filter on by hand until the gasket touches the engine, then turn it an additional three-quarters of a turn. Hand-tight is correct; an oil filter wrench is for removal only.

Add new oil and check the level

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. Pour in the amount of oil your manual specifies, usually starting with one quart less than the total capacity. Wait a minute for the oil to settle in the pan, then check the level with the dipstick.

Pull the dipstick all the way out, wipe it clean on a rag, and reinsert it fully. Pull it out again and look at where the oil level sits. Most dipsticks have a minimum and maximum mark — the level should be at or near the maximum. Add oil in small amounts if needed, checking after each addition. Screw the oil filler cap back on once you reach the correct level.

Start the engine and check for leaks

Start the engine and let it run for 30 seconds to a minute. The oil pressure light on your dashboard should come on briefly, then turn off. If it stays on, turn off the engine immediately and check that the oil filter is tight and the drain plug is secure. Once the light turns off, turn off the engine and wait five minutes for the oil to settle.

Check underneath the car for any drips around the drain plug and oil filter. A small amount of oil residue is normal, but active dripping means something is not tight. Tighten the drain plug or filter slightly if needed. Check the oil level one more time with the dipstick to make sure it is still at the correct mark.

Dispose of old oil safely

Never pour old oil down a drain, into the ground, or into the trash. Oil contaminates soil and water and is illegal to dispose of that way in most places. Pour the old oil from your drain pan into a sealed container — an empty oil jug works well. Take it to a recycling center, auto parts store, or service station that accepts used oil. Most accept it for free, and some offer a small credit toward new oil or filters.

If you removed the old oil filter, place it in a plastic bag to prevent leaks and dispose of it with the oil or at a recycling center. Some auto parts stores will take filters separately. Keep your receipt or note the date and mileage when you completed the oil change so you know when the next one is due.

Frequently Asked Questions

What if I spill oil on the driveway?

Soak up fresh spills immediately with cat litter, sand, or absorbent cloth. Sweep up the litter and dispose of it in a sealed bag. For dried stains, use a degreaser or pressure washer. Never use water alone, as oil floats on water and spreads the problem.

Can I change my oil if the engine is completely cold?

Yes, but it takes longer for the oil to drain. Warm oil flows faster and drains more completely, leaving less old oil in the engine. If you must work on a cold engine, let it run for a minute or two first, then wait five minutes before draining.

How do I know if I bought the wrong oil type?

Check the bottle against your owner's manual or the sticker inside your door jamb. The numbers and letters must match exactly — 5W-30 is not the same as 10W-30. If you bought the wrong type, do not pour it in. Return it to the store and get the correct type.

What if the oil filter is stuck and won't turn?

Tap the filter wrench gently with a hammer to break the seal, then try again. If it is still stuck, wrap a rubber band around the filter for better grip, or use a strap wrench instead of a can wrench. Apply steady pressure rather than sudden force to avoid damaging the filter housing.

Do I need to reset anything after an oil change?

Some newer cars have an oil change reminder light that you can reset from the dashboard menu — check your owner's manual for the steps. Older cars do not have this feature. Keeping a record of the date and mileage is the simplest way to track when the next change is due.