Draining Oil: How Much Is Left In The Pan?

How much oil is left in the pan after draining it is a question that has been asked by many car enthusiasts and mechanics alike. The answer may vary depending on the make and model of the vehicle, as well as the method used to drain the oil. Some people use an oil extractor, while others simply remove the oil drain plug. In general, it is estimated that anywhere from a few ounces to a quart of oil may be left in the crankcase or oil pan after draining. This residual oil can be attributed to the various oil passages, pumps, and crevices within the engine. Additionally, the temperature of the oil and the efficiency of the drainage method can also impact the amount of oil left behind.

Oil extractor vs drain plug

There are two popular methods for changing a car's oil: using an oil extractor or via the drain plug. Both methods have their pros and cons, and the best option depends on individual preferences and circumstances. Here is a detailed comparison of the two processes.

Oil Extractor

The oil extractor uses a vacuum mechanism to suck oil directly from the crankcase. It has a long tube that is inserted into the dipstick pipe to reach the bottom of the oil pan. By pumping the handle, a vacuum is created, and the oil is collected in an attached container. This process is clean, and there is no need to raise the car. However, it may not extract all the sludge, as it is heavy and can't be sucked through the thin tube. Other disadvantages include the need for a lot of compressed air supply and the possibility of the tubes being too short. If the oil filter is situated under the car, the car will need to be lifted, defeating one of the main advantages of this method.

Pros:

• Easiest way to suction out engine oil.
• No need to raise the car.
• No chance of oil leaks.
• Requires fewer tools.

Cons:

• Cannot extract sludge.
• Needs a lot of compressed air supply.
• The tubes can be too short.
• If the oil filter is underneath, the car will need to be lifted.

Drain Plug

The drain plug is a large screw or plug located under the oil pan of the engine. To change the oil using this method, the car must be lifted, and a container placed under the drain plug to collect the oil. This process is quick and drains out all the oil, including precipitates. However, it can be messy, as oil may spill if the drain pan is not correctly placed. There is also a risk of damaging the oil pan, especially if it is made of soft metal or plastic.

Pros:

• Quickest way to suction out engine oil.
• All the oil, including precipitates, is drained out.

Cons:

• Messy if the drain pan is not placed correctly.
• Need to raise the car to access the drain plug.
• Risk of damaging the oil pan.

Both the oil extractor and drain plug methods have their advantages and disadvantages. If speed is a priority, the drain plug method is preferable. On the other hand, the oil extractor is a good option for those who value cleanliness and want to avoid raising their car. Ultimately, the choice depends on individual preferences and the specific circumstances of each car.

How much oil is left in the engine after draining?

It is impossible to drain all the oil from an engine. The amount of oil left in the engine after draining varies depending on the engine and the method used to drain the oil.

Some engines retain a significant amount of oil, while others only retain a small amount. Factors that can affect the amount of oil retained include the design of the engine, the presence of oil coolers, and the use of anti-drain back check valves.

When using a traditional drain plug method to drain the oil, it is estimated that between 0.5 to 1.5 quarts of oil may be left in the engine. This can vary depending on the size and type of engine, as well as the effectiveness of the draining process.

Oil extractors are another method used to drain oil, and they can leave behind a negligible amount of oil. However, it is important to note that not all oil extractors are created equal, and some may be more effective than others. Additionally, the placement of the extractor hose can impact the amount of oil extracted.

To ensure that as much oil as possible is drained from the engine, it is recommended to warm up the engine before draining, allow sufficient time for the oil to drain, and consider changing the oil filter with each oil change.

How to check the oil level

Checking the oil level in your car is essential to maintaining its life. Here is a step-by-step guide on how to check the oil level in your car:

Step 1: Prepare to Check

Park your vehicle on level ground with the engine off, the transmission in Park (or the manual transmission in a lower gear), and the parking brake on. Make sure you have a lint-free rag or a scrap of old fabric to wipe the dipstick.

Step 2: Locate the Dipstick

Open the hood of your car. The dipstick on most vehicles is easy to spot, as it has a small coloured handle—usually yellow or orange—marked with an oil-can symbol. It is typically located towards the passenger side or near the front of the engine block.

Step 3: Pull the Dipstick

Pull the dipstick out of the tube. Wipe any oil off of the end of the dipstick with a rag or paper towel. On the dipstick, you will see two lines or markings: the lower one indicates that the oil level is one quart low, and the upper line denotes that the crankcase (the car's oil tank) is full. Some dipsticks are also marked with the words "full" and "add."

Step 4: Note Oil Level

Insert the dipstick into the tube slowly and push it all the way down. Now, withdraw it and look closely at the tip, which should have oil on it. If the level of the oil is between the two lines, your vehicle has enough oil. If it's at the low mark or below, add a quart of oil.

Step 5: Wait and Re-check

Once you've added a quart of oil, wait several minutes for the oil to drain down into the crankcase, and then check the oil level again. The oil level should be at least between the high and low marks. The oil level does not have to be at the high mark for your engine to have enough lubrication to run safely.

How to drain oil from your car

Changing your car's oil is a simple task that can save you money and keep your car in good condition. Here's a step-by-step guide on how to drain the oil from your car:

Step 1: Warm Up the Engine

Start your car and let it run for 2-3 minutes to warm up the engine. This will help the oil flow out of the engine more easily. Make sure the engine is only slightly warm to the touch, as you don't want it too hot. Then, shut off the engine.

Step 2: Locate the Drain Plug

Look under your car to find the drain plug. It is usually a large nut or plug located under the oil pan at the bottom of the engine. If it's not easily accessible, you may need to crawl under the car or jack up the car to reach it.

Step 3: Place a Container Under the Drain Plug

Place a container under the oil drain plug to catch the oil. Make sure the container is big enough and can hold at least twice the amount of oil your engine takes.

Step 4: Remove the Oil Cap

Open the vehicle's hood and locate the oil cap on top of the engine. It is usually about 2 inches (5.1 cm) across and has an oil symbol or the word "oil" on it. Unscrew the oil cap counterclockwise and set it aside.

Step 5: Unscrew the Oil Plug

Using a socket or crescent wrench, unscrew the oil plug counterclockwise. You may need to apply inward force as if you are pushing the plug back into the hole while removing it to avoid spilling oil on your hand. Once the bolt is unscrewed, quickly pull it away and remove the metal washer between the oil pan and the drain plug.

Step 6: Let the Oil Drain

Wait for 2-3 minutes to allow all the oil to drain out of the engine. When no more oil is dripping from the drain hole, clean the drain-hole threads and the surrounding area with a clean cloth. Also, clean and inspect the drain plug and its washer or gasket. Replace it if it is worn or broken.

Step 7: Replace the Drain Plug

Once the oil has drained completely, put the washer back in place and reinsert the drain plug. Tighten it back into the oil pan by turning it clockwise, but be careful not to overtighten it.

Step 8: Lower the Vehicle

If you jacked up the car, now is the time to lower it back down. Make sure the drain pan is still in place to catch any remaining oil.

Step 9: Dispose of the Old Oil

Transfer the old oil from the drain pan to a sealable waterproof container, such as the newly emptied oil container. Clearly mark the container as "used engine/motor oil." You can dispose of the old oil at designated oil-collection sites, which are often found at places that sell motor oil or service stations that do oil changes.

And that's it! You have successfully drained the oil from your car. Remember to always dispose of old oil properly and recycle it whenever possible.

How often should you change your oil?

The frequency with which you should change your oil depends on several factors, including the age of your car, the type of oil used, and your driving conditions. Let's delve into each of these factors to determine the optimal oil change interval for your vehicle.

Oil Change Intervals for Older Cars

Older vehicles typically have oil change recommendations based on mileage and driving conditions. Owner's manuals often provide two maintenance schedules: one for "normal" operation and another for "severe service." Severe service conditions include frequent short trips (5 miles or less), extreme temperatures or dusty climates, sustained stop-and-go driving, and towing or carrying heavy loads. If your driving habits fall under the severe service category, it's best to follow the more rigorous maintenance schedule. However, if your car is used under normal conditions, you may not need to change the oil as frequently.

Oil Change Intervals for Newer Cars

Modern vehicles are often equipped with oil-life monitoring systems that automatically notify you when an oil change is necessary. These systems analyse actual vehicle operating conditions to determine when the oil will begin to degrade. In some newer cars, the concept of "severe service" is eliminated altogether because the oil-life monitoring system adjusts the oil change interval based on the vehicle's usage. It is important to reset the oil-life monitoring system after each oil change, either by a service technician or by following the instructions in the owner's manual if you change the oil yourself.

Type of Oil Used

The type of oil used also plays a crucial role in determining oil change intervals. Conventional oil typically requires changes more frequently, usually between 3,000 to 5,000 miles. Synthetic-blend or full-synthetic oils, on the other hand, can last much longer. With modern lubricants, engines using these types of oil may have recommended oil change intervals of 5,000 to 7,500 miles or even up to 15,000 miles for certain full-synthetic motor oils.

Driving Conditions

Your driving habits and conditions can significantly impact the frequency of oil changes. If your vehicle is primarily used for short trips, operated in extreme climates, or subjected to sustained stop-and-go driving, you may need to change the oil more often. Additionally, if you frequently tow a trailer or carry heavy loads, this can also affect the oil change interval. It is important to refer to your owner's manual to determine the recommended maintenance schedule based on your specific driving conditions.

In summary, the recommended oil change interval for your vehicle will depend on a combination of factors, including the age of your car, the type of oil used, and your driving conditions. By following the guidelines provided in your owner's manual and staying vigilant about monitoring your oil levels, you can help ensure the optimal performance and longevity of your vehicle.

Frequently asked questions