What happens when you change your oil and filter

An oil and filter change removes the old oil circulating through your engine and replaces it with fresh oil, along with a new filter that catches particles and debris. Over time, oil breaks down from heat and friction, losing its ability to protect engine parts. The filter clogs as it traps contaminants. Changing both together keeps your engine running smoothly and extends its life.

The process takes 30 minutes to an hour if you do it yourself, or about the same time at a shop. You'll drain the old oil into a pan, unscrew the old filter, install a new one, add fresh oil, and check the level. Most people do this every 3,000 to 10,000 miles depending on their car and oil type — check your owner's manual for the exact interval.

Key Takeaways

  • You need an oil drain pan, a wrench to fit your drain plug, a filter wrench, fresh oil in the correct type and amount for your car, and a new filter that matches your vehicle model.
  • The drain plug sits underneath the engine; you unscrew it to let old oil flow into a pan, then replace the plug before adding new oil.
  • The oil filter screws on by hand and comes off the same way once you've drained most of the old oil; you coat the rubber gasket on the new filter with fresh oil before installing it.
  • After filling with new oil, you start the engine, let it run for a minute, turn it off, wait five minutes, then check the dipstick to confirm the level is correct.

Gather your supplies before you start

You need the right oil type and amount for your specific car. Open your owner's manual or look at the oil cap under the hood — it usually shows something like "5W-30" or "10W-40." Write down that number and the capacity (often 4 to 6 quarts). Buy oil that matches both. You also need a new filter; bring your car's year, make, and model to an auto parts store and they'll hand you the correct one.

For tools and equipment, get an oil drain pan (a shallow rectangular pan that holds at least 6 quarts), a wrench that fits your drain plug (usually 13mm, 14mm, or 15mm — ask at the parts store if unsure), and a filter wrench (a metal band or cup that grips the filter). You'll also want a jack and jack stands if your car sits low and you need clearance to reach the drain plug, plus rags or paper towels. Some people use a funnel to pour oil without spilling.

Locate and drain the old oil

Warm up your engine by running it for a minute or two, then turn it off. This makes the oil flow more easily. Raise the car safely with a jack if needed and find it with jack stands — never work under a car supported only by a jack. Locate the drain plug underneath the engine; it's a bolt sticking down from the oil pan. Position your drain pan underneath it.

Loosen the drain plug with your wrench by turning it counterclockwise, then unscrew it by hand once it's loose enough. Oil will pour out — it may still be warm, so be careful. Let it drain completely, which 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. Don't over-tighten; snug is enough.

Remove and install the new filter

The oil filter is a cylindrical canister bolted to the side of the engine. Position your drain pan underneath it because old oil will spill when you remove it. Use your filter wrench to loosen it by turning counterclockwise, then unscrew it by hand. Tip it carefully to drain the last bit of oil into the pan.

Before installing the new filter, coat the rubber gasket (the ring on top) with a thin layer of fresh oil — this helps it seal properly. Screw the new filter on by hand until the gasket touches the engine, then turn it another three-quarters of a turn. Don't use the wrench to tighten it; hand-tight is correct. If you over-tighten, it becomes difficult to remove next time.

Add new oil and check the level

Lower the car back to the ground if you raised it. Locate the oil filler cap on top of the engine — it usually has an oil can symbol on it. Unscrew it and set it aside. Place a funnel in the opening if you have one, then pour in the amount of oil your manual specified. Start with slightly less than the full amount; you'll check the level after the engine runs.

Screw the oil cap back on. Start the engine and let it run for about a minute so the new oil circulates and the filter fills. Turn off the engine and wait five minutes for the oil to settle back into the pan. Pull out the dipstick (a long thin rod with markings on it), wipe it clean with a rag, reinsert it fully, then pull it out again to read the level. The oil should reach the "full" mark. If it's low, add a bit more and check again.

Dispose of old oil properly

Never pour old oil down a drain or into the ground — it contaminates water and soil. Most auto parts stores accept used oil for free, even if you didn't buy supplies from them. Pour your old oil into a clean container with a lid (an empty oil jug works perfectly) and take it to a store like AutoZone, O'Reilly, or Advance Auto Parts. Some recycling centers also accept it.

If you removed the old filter, many parts stores will take that too. Call ahead to confirm they accept filters in your area, as policies vary. Keep your receipt if you need documentation for environmental compliance at work.

Record your maintenance and plan the next change

Write down the date, mileage, and oil type you used. Keep this record in your glove box or a notes app on your phone. Your next oil change is due when you reach the mileage interval in your manual — typically 3,000 miles for conventional oil, 5,000 to 7,500 for synthetic blend, or 7,500 to 10,000 for full synthetic. Some newer cars go longer; always check your manual.

Set a phone reminder for the mileage or date so you don't forget. Changing oil on schedule prevents sludge buildup, keeps your engine running efficiently, and protects your warranty if it's still active. If you're unsure about any step, a shop can do the work for $30 to $75 depending on your location and oil type.

Frequently Asked Questions

Can I change the oil without raising the car?

If your car sits high enough that you can fit a drain pan underneath the plug while lying on your back, yes. Most sedans and smaller vehicles need to be raised. Use a jack and jack stands — never rely on a jack alone. If you're uncomfortable working under a car, a shop is the safer choice.

What if I spill oil on the driveway?

Soak it up with cat litter, sand, or oil absorbent material from an auto parts store. Let it sit for 15 minutes, then sweep it up and dispose of it in the trash. For large spills, contact your local environmental agency for guidance on cleanup and reporting requirements.

Do I need to change the filter every time I change the oil?

Yes. The filter clogs as it traps debris, and a clogged filter reduces oil flow to the engine. Changing it with every oil change ensures your engine stays protected. Some people change the filter every other oil change, but your manual will specify what's recommended for your vehicle.

What if the drain plug is stuck and won't loosen?

explore penetrating oil like WD-40 around the plug and let it soak for 15 to 30 minutes. Try again with your wrench, explore steady pressure rather than jerking. If it still won't budge, a shop has tools to remove stuck plugs without damaging the pan. Don't force it — you risk stripping the threads.

Can I use a different oil type than what my manual says?

No. Your engine is designed for a specific viscosity and type. Using the wrong oil can reduce protection, affect fuel economy, or damage the engine over time. If you're unsure whether to use synthetic or conventional, your manual or dealer can advise based on your driving habits and climate.