Motor oil is an essential component of your vehicle. Just like your heart requires proper blood flow to function well, your engine needs the right type of oil to keep it running smoothly. This leads to the question “What happens if you put the wrong oil in your car?”.

Motor oil goes from the basic, conventional varieties to the higher-end synthetic types. If you put the wrong oil in your car, and you move from a higher grade to a lower grade of oil, it can impact the performance of the vehicle and potentially void the warranty. Conversely, if you upgrade from regular oil to a synthetic variety, you will see the opposite effect — a smoother drive and a better operating engine. 

What Is Motor Oil? 

According to Pennzoil, “Historically, motor oil was just a mixture of base oil and additives used to lubricate engine parts, reduce friction, clean, cool, and protect the engine.” The base oil, or petroleum, is a naturally occurring fossil fuel that is extracted from pockets of rock under the surface of the earth.

However, this substance is essential for ensuring that your car functions correctly. In addition to the basic functions, it is also “responsible for engine wear protection and engine performance enhancement as well as complete protection of all moving parts.”

However, there are four main types of oil. The one that you need is highly dependent on a variety of factors. These include your vehicle type, the climate you live in, the amount you drive as well as your overall mileage. Without choosing the right one, you could risk your vehicle running poorly or even not functioning at all.

Types Of Motor Oil

Conventional Motor Oil

This is the most common type of motor oil. It is simple and affordable. However, it is ideal for late-model vehicles that do not accumulate a lot of mileage each year. Moreover, it is best to use this option when you do not have an intricate engine design. 

Synthetic Motor Oil

Conversely, synthetic oil is a high-end option that is best suited for high-performance vehicles. While your mind may immediately go to a Ferrari or Lamborghini, this also refers to anyone who is towing or hauling large amounts of cargo. 

Additionally, this product performs better in extreme temperatures, both hot and cold. This is due to the thinner consistency that comes with a higher viscosity. In fact, according to the Universal Technical Institute, “In cold weather, thin oils reduce friction and help engines to start quicker.

In higher temperatures, thick oils maintain oil pressure and film strength, and support heavier loads.” Thus, if you reside in places with high heat thresholds like Nevada, Texas, or California, or harsh winters such as Wisconsin or Michigan, this is an ideal product for you. 

Furthermore, synthetic motor oil is chemically formulated to prevent oil sludge build-up, prevent engine drag and maintain a higher viscosity. What does all of this mean? First, you can go longer in between oil changes. Next, you will improve your fuel efficiency. Finally, the engine will be more lubricated, meaning better performance. 

Synthetic Blend Motor Oil

Synthetic blend motor oil is the happy medium between conventional and synthetic varieties. This essentially equates to a more affordable product that still better protects the engine than the conventional version.

Moreover, both full synthetic and synthetic blends decrease oxidation (which can degrade the quality of the oil) and they perform well in extreme climates. 

Furthermore, if you are hoping to transition to synthetic oil in the car, this is the perfect tool to help with this adjustment. That is because this motor oil contains a mixture of base oils from both the conventional and synthetic oil types. 

High-Mileage Motor Oil

Lastly, there is the high-mileage motor oil, which as the name implies, is made for cars that have high mileage. Thus, if your vehicle has over 75,000 miles this is the best oil for your engine, whether the vehicle is old or new.

It is tailor-made to help lower oil burn-off and consumption. This type of oil will also reduce the risk of smoke and exhaust when driving the vehicle.  

What Happens If You Put The Wrong Oil In Your Car?

Now that you understand the difference between these oil types, it is easier to understand what will happen if you inadvertently put the wrong oil in your car.

For those with conventional oil to start, adding an improved quality of the oil is not going to cause any harm. It is actually going to improve the performance of your vehicle.

However, if you move from a full or blended synthetic oil to conventional oil, you will notice changes. This is the case for high-mileage oils as well. These can include a lower gas mileage and reduced engine performance.

Additionally, it will even cause your engine to wear out faster. It is important to note that while this will lessen the quality of your drive and age your vehicle’s engine more quickly, it will not have any short-term impacts that will lead to the vehicle not being able to drive.

Moreover, depending on your manufacturer, if you downgrade your oil from their recommendations, you could void the car’s warranty. This is an extremely important thing to consider before making a quick switch to save a few bucks.  

Lastly, contrary to popular belief, putting the wrong oil in your car will not cause oil leaks. However, for those individuals that do have a leak in their car, you are more likely to notice the issue when a thinner oil is applied.  

Considerations When Using Motor Oil

The way that your car runs is dependent on a multitude of factors. Here are some considerations that should be taken into account before making your choice of motor oil. 


Your car may run fine in South Carolina or Florida. These are locations where the temperature differential throughout the year is minor. However, if you move to Montana, this is not the case.

Thus, it might behoove you to transition to a higher quality oil. This will better equip your car to start during the frigid winter months. 

Additionally, if you live in these climates, you also need to pay more attention to the grade of your motor oil. What does this mean?

When you look at a bottle of motor oil, you will see a combination of numbers with the letter ‘W’ in between (which stands for Winter). These denote how the oil will handle both hot and cold temperatures. 

The most common motor oil grades are 5W-40, 5W-30, 10W-30, 10W-40, 15W-40 and 20W-50. The first number followed by the ‘W’ denotes the viscosity at cold temperatures. As mentioned above, you want the oil to be thin in cold climates.

Therefore, you are looking for the smallest number to get the best results. Conversely, the second number represents how the oil handles at warm temperatures. The bigger the number, the higher the weight. This means that the oil will be thicker and thus, better equipped for the warmer weather.

Car Age And Mileage

Conventional oil may have worked fine over the past few years. However, once your car reaches a certain mileage, it is best to move to high-mileage motor oil. This will accommodate your aging engine. This is a worthwhile investment that will elongate the life of your vehicle. 

Manufacturer Recommendations

Lastly, you should never go below the oil grade that the manufacturer recommends. They provide this guidance because the vehicle is designed to run off of a certain caliber of products. 

Frequently Asked Questions

Do I need a specific oil filter when using synthetic versus regular oil?

No! You can use any filter with any type of motor engine oil. When the box states that it is a synthetic oil filter, this is not referring to the oil at all. In actuality, it means that the filter is made with synthetic fibers. These can more effectively catch contaminants, giving your car a better performance. 

However, synthetic oil has fewer contaminants. Therefore, this filter will not bring much of a benefit to your vehicle. Conversely, when using conventional oil, this might be a good and cheaper investment to help improve the performance of your car.


Can you mix different motor oils?

You can mix different motor oils. However, the car’s performance is liable to decrease if it requires a higher quality product. It will also cause your engine to degrade over time.

Final Thoughts

According to the experts at CarCare, “A typical passenger car should last 200,000 miles or more”.

This will only occur if you take proper care of your vehicle. That includes getting regular oil changes and car maintenance as well as following the manufacturers’ recommendations for the make and model of your car. 

If you happen to put the wrong oil in your car, there is a chance that your performance and gas mileage can suffer. Thankfully, it will not have any long-term impacts if you don’t consistently switch between oil types. If you consider replacing the oil yourself, make sure your hood lever is operating properly first.

Using the wrong oil in your car can cause engine problems that could affect your driving. If you park your car under a tree, tree sap on your windows can be challenging to remove and impact visibility. It’s essential to use the correct oil and promptly remove any tree sap to avoid potential safety issues.

To listen to the radio without starting the car, use the accessory mode or an external power source. But be cautious, as leaving the radio on for too long can drain the car’s battery. Using the correct oil type and grade is important to avoid engine damage and warranty issues.



Welcome to my car seat blog! As a mom of 3, I put together with other hard-working moms a highly informative one-stop car seat resource, full with many reviews and buyer guides. I hope you find it invaluable. Thank you for trusting me & my team! - Keren

Keren Simanova

Welcome to my car seat blog! As a mom of 3, I put together with other hard-working moms a highly informative one-stop car seat resource, full with many reviews and buyer guides. I hope you find it invaluable. Thank you for trusting me & my team! - Keren