What happens during an oil change, and why you do it yourself

An oil change means draining the old oil from your engine, replacing the oil filter, and filling the engine with fresh oil. You do this yourself to save money — a shop charges $40 to $100 or more, while the materials cost $20 to $40. The work takes 30 minutes to an hour once you have done it once.

Oil breaks down over time and collects dirt and metal particles. Fresh oil lubricates moving parts, reduces heat, and keeps your engine running longer. Most cars need an oil change every 5,000 to 7,500 miles, though some newer vehicles go 10,000 miles between changes. Check your owner's manual for the exact interval and the oil type your engine needs.

The basic steps are the same across most cars: warm the engine, drain the old oil, replace the filter, add new oil, and check the level. The main variables are where the drain plug sits, how the filter twists off, and whether you need to lift the car or crawl underneath from the side.

Key Takeaways

  • You need the correct oil type and amount for your car — check your owner's manual, not the bottle at the store, because different engines need different weights.
  • Warm the engine for two or three minutes before draining so the oil flows faster, but let it cool enough that you can touch the drain plug without burning yourself.
  • The oil filter wrench and drain pan are the only tools most people need to buy; you probably already have a socket wrench and jack.
  • After adding new oil, wait a minute for it to settle in the pan, then check the dipstick — overfilling damages the engine as much as underfilling does.

Gather the right materials before you start

You need four things: the correct oil for your engine, a new oil filter, an oil drain pan, and an oil filter wrench. The oil type and amount are printed in your owner's manual — usually something like "5W-30" or "0W-20" and a quantity like "5 quarts." Do not guess or use what worked in your last car. Different engines have different needs, and using the wrong oil voids some warranties.

Buy the oil filter that matches your car's year, make, and model. The part number is in your manual or on the old filter itself. An oil filter wrench is a metal band or cup that grips the filter so you can unscrew it by hand — they cost $8 to $15 and fit most filters. A drain pan catches the old oil so it does not spill on your driveway; a basic plastic one costs $5 to $10.

You will also need a way to lift the car safely. A floor jack and jack stands work, or you can drive onto ramps if your driveway is level. Never work under a car supported only by a jack — use stands or ramps as a backup. If you do not own these, borrow them or do the work at a friend's house rather than buy them for one oil change.

Drain the old oil and remove the filter

Start by warming the engine. Run it for two or three minutes so the oil thins and drains faster, then turn it off. Wait long enough that you can touch the drain plug without burning your hand — about five minutes. A warm engine drains much faster than a cold one, but you do not want to burn yourself.

Lift the car safely using a jack and stands, or drive onto ramps. Locate the drain plug underneath the engine — it is a bolt sticking down from the oil pan. Place your drain pan underneath it, then unscrew the plug by hand or with a wrench. The oil will pour out; let it drain completely, which takes five to ten minutes. Once the flow slows to a drip, wipe the plug clean with a rag and set it aside.

Find the oil filter, which is usually a metal cylinder screwed onto the engine. Place the drain pan underneath it to catch the oil still inside. Use the filter wrench to loosen it, then unscrew it by hand the rest of the way. Oil will spill, so keep the pan close. Wipe the rubber gasket area on the engine clean with a rag so the new filter seats properly.

Install the new filter and add fresh oil

Take the new filter and coat the rubber gasket — the ring at the top — with a thin layer of fresh oil. This helps the gasket seal and makes removal easier next time. Screw the filter onto the engine by hand until the gasket touches, then turn it another three-quarter turn. Do not use the wrench to tighten it; hand-tight is correct. Over-tightening makes it stick and wastes time next oil change.

Reinstall the drain plug. Wipe it clean, then screw it back in by hand first, then tighten it with a wrench. Do not over-tighten — you want it snug, not stripped. Most drain plugs need only a quarter-turn after hand-tight.

Lower the car back to the ground. Open the hood and locate the oil filler cap, usually labeled "Oil" on top of the engine. Unscrew it and set it aside. Pour in the amount of oil your manual specifies, usually in half-quart increments. Pour slowly so you do not overfill. Replace the cap when done.

Check the oil level and run the engine

Wait one minute for the oil to settle into the pan, then pull out the dipstick — a long metal rod with markings on it. Wipe it clean on a rag, reinsert it all the way, then pull it out again. The oil should reach the "full" line. If it is below that line, add a little more oil and check again. If it is above the line, you have overfilled; drain a small amount into the pan until it is correct.

Start the engine and let it run for 30 seconds to a minute. The oil light on your dashboard should turn off within a few seconds. If it stays on, turn off the engine, wait a minute, and check the dipstick again. If the level is correct and the light is still on, there may be an air pocket in the filter — run the engine for another minute and check again.

Turn off the engine, wait five minutes, and check the dipstick one more time. The level should still be at the full line. If it has dropped, add a small amount more. Once the level is correct and the light is off, you are done. Dispose of the old oil and filter at a recycling center or auto parts store — most accept them for free.

Common mistakes that damage your engine

Overfilling the oil is the most common mistake. Too much oil foams, loses its ability to lubricate, and can damage seals and gaskets. Underfilling starves the engine of oil and causes wear. Both are straightforward to avoid by checking the dipstick twice — once after adding oil and once after running the engine.

Using the wrong oil type or weight is the second mistake. A manual that says "5W-30" does not mean "any 30-weight oil" — the 5W part matters just as much. Using a thicker oil than specified can clog the filter and reduce flow; using a thinner oil can cause wear. Read your manual, not the shelf at the store.

Over-tightening the drain plug or filter is common and causes leaks later. The drain plug should be snug but not cranked down with all your strength. The filter should be hand-tight plus three-quarter turn, no more. If you strip the drain plug hole, you will need a new oil pan — a much bigger repair.

Forgetting to replace the drain plug washer is less common but catastrophic. Some drain plugs have a crush washer that seals the connection. If your old plug has one and the new one does not, transfer the washer or buy a new one. Without it, the plug will leak.

When to take your car to a shop instead

If your car is very low to the ground and you cannot fit underneath safely, a shop is the right choice. Some sports cars and luxury vehicles sit so close to the pavement that a standard jack and ramps do not work. Trying to force it risks dropping the car on yourself.

If the drain plug or filter is stuck so tight that you cannot budge it, a shop has tools and experience to remove it without stripping it. Forcing a stuck plug can crack the oil pan. If you have already tried and feel resistance, stop and take it in.

If your car has an electronic oil-level monitor instead of a dipstick, you may need a shop computer to reset it after the change. Some newer cars require this step, and doing it wrong leaves a false warning light on. Check your manual to see if this applies to you.

Frequently Asked Questions

How do I know what oil type my car needs?

Open your owner's manual and search for "oil" or "fluid capacities." You will find a line that says something like "5W-30" or "0W-20" and the total amount in quarts. That is the only specification that matters. The manual is specific to your year, make, and model, so it is always correct.

Can I pour old oil down the drain?

No. Used motor oil is toxic and damages water supplies. Take it to a recycling center, auto parts store, or quick-lube shop — most accept it free. Some will also take the old filter. Never pour it down a drain or into the ground.

What if the oil light stays on after I change the oil?

First, check the dipstick to confirm the level is correct. If it is, run the engine for another minute — sometimes an air pocket in the new filter takes time to clear. If the light is still on after that, the sensor itself may be faulty. A shop can test it, but it is not an emergency.

How often should I check my oil between changes?

Check it once a month or before a long drive. Pull the dipstick, wipe it, reinsert it fully, then pull it out and read the level. It should be between the minimum and maximum marks. If it is below minimum, add a quart and check again in a week — a slow drop is normal, but a fast drop means a leak.

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

Yes. The filter traps dirt and metal particles, and after 5,000 to 7,500 miles it is full. A clogged filter reduces oil flow and defeats the purpose of the change. Always replace it at the same time you change the oil.