The Complete Guide to Change Engine Oil: Everything You Need to Know for a Successful DIY Job​

Changing your engine oil yourself is a straightforward, cost-effective task that can significantly extend your car's life and improve its performance. With basic tools, a little time, and by following this detailed guide, any car owner can safely and correctly change their engine oil, saving money and ensuring their vehicle runs smoothly for years to come. This process involves draining the old oil, replacing the oil filter, and refilling with new, clean oil, all while adhering to critical safety and environmental practices.

​Why Regularly Changing Your Engine Oil is Non-Negotiable​

Engine oil is the lifeblood of your vehicle's engine. Its primary job is to lubricate the hundreds of moving metal parts inside the engine, reducing friction and preventing them from grinding against each other and wearing out prematurely. Over time and with use, engine oil breaks down. It becomes contaminated with microscopic metal particles from engine wear, fuel soot, dirt, and other combustion by-products. This contamination turns the oil from a smooth lubricant into a gritty, abrasive slurry. When oil degrades, it cannot lubricate effectively. This leads to increased engine wear, higher operating temperatures, reduced fuel efficiency, and ultimately, the risk of catastrophic engine failure. ​Regular oil changes​ flush out this contaminated oil and replace it with fresh, effective lubricant. This simple act is the single most important preventative maintenance task you can perform for your engine. It preserves horsepower, maintains gas mileage, and prevents expensive repairs. Manufacturers provide specific oil change intervals in your owner's manual, and following these is essential. For many modern vehicles, this is between 5,000 to 10,000 miles, but older cars or those used in severe conditions—like frequent short trips, extreme heat or cold, or towing—require more frequent changes.

​Gathering the Essential Tools and Materials​

Before you begin, you must have all the correct items on hand. Trying to find a tool while you have oil draining is frustrating and messy. Here is the complete list of what you will need.

​New Engine Oil:​​ Check your owner’s manual for the exact specification. You need the correct viscosity (e.g., 5W-30) and the right type (conventional, synthetic blend, or full synthetic). Also note the oil capacity, usually listed in quarts or liters. Purchase one extra quart to account for spillage or to top up later. ​Using the wrong oil can cause engine damage.​​

​A New Oil Filter:​​ The oil filter must match your vehicle’s make, model, and engine size. You can find this information in an auto parts store catalog or online. There are two main types: cartridge filters that require a housing and spin-on filters that are a single unit. Know which one your car uses.

​Basic Tools:​​

• A set of ​socket wrenches and ratchets​ with both metric and standard sockets.
• An ​oil filter wrench​ for removing the old filter. Types include strap wrenches, cap-style wrenches, and claw wrenches. The cap-style that fits over the end of the filter is often the most effective and prevents crushing the filter.
• A ​drain pan​ specifically for used oil. It should hold at least 50% more than your engine's oil capacity.
• A ​funnel​ to pour new oil without spilling.
• ​Latex or nitrile gloves​ to keep your hands clean.
• ​Safety glasses​ to protect your eyes from drips.
• ​Jack and jack stands, or vehicle ramps.​​ You must never work under a vehicle supported only by a jack. ​Jack stands or ramps are absolutely mandatory for safety.​​ A hydraulic floor jack makes lifting easier.
• A ​wheel chock​ to prevent the car from rolling.
• ​Cleaning rags​ or paper towels.

​Optional but Helpful Items:​​

• A ​torque wrench​ for precisely tightening the drain plug to the manufacturer's specification.
• A ​drain plug gasket or crush washer.​​ Many drain plugs use a one-time crush washer that should be replaced with every oil change to prevent leaks.
• Cardboard or a tarp to lie on and catch spills.
• A ​fluid transfer pump​ for vehicles where the oil is extracted via the dipstick tube, though this guide focuses on the traditional drain method.

​Critical Safety Preparations Before You Start​

Your safety is the top priority. Never skip these steps.

First, ensure you are working in a well-ventilated area, preferably a flat, concrete driveway or garage floor. Engage the parking brake fully. If your vehicle has an automatic transmission, place it in "Park." If it is a manual transmission, place it in first gear or reverse. Use a wheel chock on a tire that is diagonally opposite the end you are lifting. For example, if you are lifting the front of the car, chock a rear tire.

​The most important safety rule is to never get under a vehicle supported only by a hydraulic or scissor jack.​​ Jacks are for lifting only. Once the car is lifted, you must place it securely on ​jack stands rated for your vehicle's weight.​​ Place the stands on designated lift points, usually a reinforced section of the frame or pinch weld, as shown in your owner's manual. Give the car a solid shake after it is on the stands to confirm it is stable. If using ramps, ensure they are centered and the wheels are squarely on the ramp surfaces. Let the engine cool for at least 30 minutes if it has been running. A hot engine and hot oil can cause severe burns.

​Step 1: Preparing the Vehicle and Locating Key Components​

With the car safely elevated and supported, gather your tools and materials nearby. Open the hood and locate the ​oil filler cap​ on top of the engine. Remove it. This simple step allows air to enter the engine as the old oil drains, creating a smooth, complete flow. Next, locate the ​oil drain plug.​​ It is a large bolt, typically 13mm to 19mm, on the bottom of the engine's oil pan. The oil pan is the lowest metal pan under the engine. Identify the ​oil filter.​​ It is a cylindrical metal canister, usually black or white, screwed onto the engine block. On some vehicles, it is accessible from the top of the engine bay, but on most, it is underneath, near the oil pan. Knowing the locations of the drain plug and filter before you get under the car will save time. Place your drain pan directly under the drain plug. It is wise to also place some cardboard or a rag under the area of the oil filter, as some oil will spill when you remove it.

​Step 2: Draining the Old Engine Oil​

Put on your gloves and safety glasses. Using the correct socket, place the wrench on the drain plug. Before turning it, position the drain pan so the plug is centered over it. The initial flow of oil will be straight down. Turn the drain plug counterclockwise to loosen it. For the last few turns, do it by hand, but be prepared for hot oil to start flowing immediately. Once loose, quickly unscrew and remove the plug, letting it fall into the drain pan. Allow the oil to drain completely. This can take 5 to 15 minutes. Do not rush this step. While the oil drains, inspect the old drain plug. If it has a metal or rubber crush washer, remove it. Clean the plug with a rag. You will install a new washer before reinserting it. Once the stream of oil reduces to a slow drip, you can proceed. Carefully move the drain pan to be under the oil filter.

​Step 3: Removing and Replacing the Oil Filter​

The oil filter is full of old, dirty oil. Wipe any dirt or grime from around the base of the filter with a rag. Use your oil filter wrench to turn the filter counterclockwise to loosen it. It may require significant force initially. Once it is loose, you can finish unscrewing it by hand. Keep the filter upright as you lower it to minimize spills. Tip the open end of the old filter directly into the drain pan to empty the oil trapped inside. Set the old filter aside in the drain pan or on a rag.

Now, prepare the new filter. Take a small amount of fresh, new engine oil on your finger and lightly lubricate the rubber gasket on the top of the new filter. This ensures a proper seal and prevents the gasket from tearing or binding when you install it. Do not lubricate the threads. Check that the old filter’s gasket came off with the filter. It is a common error to have the old gasket stuck to the engine, and installing a new filter on top of it will cause a massive leak. Wipe the filter mounting surface on the engine block clean. Screw the new filter onto the engine by hand. Turn it clockwise until the gasket makes contact with the mounting surface. Then, give it another three-quarter to one full turn by hand. Do not use the filter wrench to tighten it. ​Overtightening the oil filter is a frequent mistake​ that can distort the gasket and cause a leak or make the next removal nearly impossible. Hand-tight is sufficient.

​Step 4: Reinstalling the Drain Plug and Adding New Oil​

Return to the drain plug. Take your new crush washer and slide it onto the plug if it uses one. Carefully thread the drain plug back into the oil pan by hand. This prevents cross-threading the threads, which can ruin the oil pan. Once it is snug by hand, use the wrench to tighten it. The proper tightness is crucial. It should be snug but not overly forced. If you have a torque wrench, consult your manual for the specification, which is often between 20 to 30 foot-pounds. If not, a firm, moderate pull on a standard wrench is adequate. ​An over-tightened drain plug can strip the threads in the aluminum oil pan, leading to a very expensive repair.

Now, lower the vehicle from the jack stands or ramps carefully. Ensure the area is clear. With the car on level ground, it is time to add the fresh oil. Locate the oil filler cap on the engine (you already removed it). Insert your funnel. Refer to your owner’s manual for the correct oil capacity. Start by pouring in about one quart less than the full capacity. For example, if your car holds 5 quarts, pour in 4. Replace the oil filler cap. Wait a minute for the oil to settle into the oil pan.

​Step 5: Checking the Oil Level and Inspecting for Leaks​

Pull out the engine’s ​dipstick. Wipe it clean with a rag, fully reinsert it, then pull it out again to get an accurate reading. Look at the end of the dipstick. It will have markings for "Full" and "Add" or have cross-hatched areas. The oil should be between these marks. If the level is low, add more oil, a half-quart at a time, checking the dipstick after each addition until the level reaches the "Full" mark. Do not overfill. ​Overfilling with oil can cause foaming and aeration, which reduces lubrication and can damage the engine. It is better to be slightly under the full mark than over it, as you can always add a little more.

Once the oil level is correct, the critical final step is to check for leaks. Do not start the engine yet. Look underneath the car at the drain plug and around the oil filter for any fresh drips. If you see none, start the engine. Let it run for about 30 seconds to a minute. The oil pressure light on your dashboard should go out within a few seconds. This indicates that the new oil is circulating. Shut off the engine. Wait another minute, then look underneath again, particularly at the drain plug and filter. Also, check the area around the oil filler cap and the top of the filter. If you see any fresh oil seeping out, tighten the component very slightly. A dry inspection means you have successfully completed the change.

​Disposing of the Old Oil and Filter Properly​

Proper disposal is a legal and environmental responsibility. Used motor oil is a toxic pollutant. Never dump it on the ground, in a drain, or with regular trash. Pour the oil from your drain pan into the original new oil containers or a dedicated, sealed container labeled for used oil. Take the used oil and the old filter to a certified collection center. Nearly all auto parts stores and many service stations accept used oil and filters for free recycling. They have special tanks for the oil. For the filter, many centers require you to drain it completely first—puncture a hole in the dome and let it drip into your drain pan for at least 12 hours. Call ahead to confirm the center’s policies. This recycling process ensures the oil is re-refined and used again.

​Determining the Correct Oil Change Frequency​

The old rule of changing oil every 3,000 miles is largely obsolete for modern vehicles and oils. The only authoritative source for your car’s oil change interval is your ​vehicle owner’s manual. It provides a schedule for "normal" and "severe" service conditions. Severe conditions include: frequent short trips under 5 miles, extensive idling, driving in very dusty or sandy conditions, towing a trailer, or operating in sustained extreme temperatures. Most people actually fall into the severe service category. If your car has an oil life monitoring system, follow its alerts, as it calculates oil life based on actual driving conditions. For vehicles without a monitor, a safe interval for conventional oil is often 5,000 miles or 6 months, and for full synthetic oil, 7,500 to 10,000 miles or 12 months. Always change the filter with every oil change.

​Common Mistakes and How to Avoid Them​

Even experienced DIYers can make errors. Being aware of them ensures a perfect job.

• ​Using the Wrong Oil or Filter:​​ Double-check your manual and the product labels. An incorrect oil filter may fit but have the wrong pressure bypass valve, causing damage.
• ​Forgetting to Replace the Drain Plug Crush Washer:​​ A reused washer can leak. Always use a new one.
• ​Overtightening the Drain Plug or Filter:​​ This strips threads or crushes gaskets. Tighten snugly by hand, then use a wrench for the plug with moderate force, and only hand-tighten the filter.
• ​Under-tightening:​​ This causes leaks. Ensure the drain plug is firm and the filter is turned until the gasket contacts, then 3/4 turn more.
• ​Leaving the Old Filter Gasket on the Engine:​​ This creates a double-gasket scenario leading to an immediate, large oil leak. Always verify the old gasket came off.
• ​Not Checking for Leaks After the Change:​​ A small leak can drain your engine of oil, leading to complete engine seizure. Always perform the pre- and post-start leak inspection.
• ​Overfilling the Engine with Oil:​​ This is as harmful as running low. Add oil slowly and check the dipstick repeatedly.
• ​Improper Disposal:​​ It is illegal and harmful. Always recycle at an approved center.

​Advanced Tips and Long-Term Maintenance Insights​

For those looking to optimize their oil changes, consider these points. Using a ​torque wrench​ for the drain plug provides precision and prevents damage. When buying oil, purchasing a well-known brand that meets the API (American Petroleum Institute) service specification listed in your manual is more important than chasing a specific brand. Full synthetic oil, while more expensive, provides superior protection, performs better in temperature extremes, and allows for longer change intervals. Keep a written log in your glove box or use a maintenance app to record the date, mileage, oil brand and viscosity, and filter used for every change. This creates a valuable history for you or a future owner. If you change your oil just before storing a vehicle for winter, the fresh oil protects the engine from acidic contaminants during storage. Finally, listen to your car. If the oil pressure warning light comes on while driving, pull over and shut off the engine immediately. Check the oil level. Unusual engine noises or performance changes can also indicate oil-related issues.

Changing your own engine oil is a rewarding and practical skill. It builds a connection with your vehicle, saves a substantial amount of money over the life of the car, and guarantees the job is done correctly with quality materials. By following this comprehensive guide, paying attention to safety, and adhering to proper disposal methods, you ensure your engine receives the care it needs for reliable, efficient operation for tens of thousands of miles. The process, from preparation to cleanup, should take a beginner about an hour. The peace of mind and financial benefit make it time well invested.