This article will help you choose the best engine oil for your car, and provide you with all the important information on what to look for. In addition, we have made lists of the best engine oil brands and oil filters to prepare you ideally for the next oil change.

Choosing the right engine oil for your car may not seem very important at first, but it is of great importance to the vehicle. Quality is definitely beneficial for the lubrication of an engine, but it doesn’t have to be expensive. The viscosity alone does not say much about the actual quality of an engine oil. Even inexpensive engine oils perform well in practice, and can easily meet the requirements for the preservation and longevity of the engine. For many, this can be very confusing. To make things even more difficult, there are countless types of motor oils on the market, which are offered at different price categories, and have different properties. So, how do you choose the best engine oil for your car?

The Best Engine Oil Brands

Before we go deeper into the functions and properties of modern motor oils, here is a list of selected brands with our recommendations for you.

☞ We took a close look at all the products and added only trusted engine oils to the list. If you have experienced any problem with one of the listed engine oils, feel free to let us know so that we can improve our recommendations. The list was last updated in 2018.

The Purpose of Engine Oil

The oil supply in the engine is used to reduce the friction of sliding and rolling engine parts. This includes the friction between the bearings, the camshafts with the valves, the crankshaft with the connecting rods and the piston rings along the cylinder wall. In addition, lubricants can be used for heat dissipation, cooling or protection against corrosion. While one often thinks of air and water in engine cooling, engine oil performs this task in the interior of the engine. In some cases, the oil used can even serve to dampen noise. But the primary task of motor oils is the lubrication of mechanical components in the engine. For this purpose, they are manufactured engine-specific and vehicle-specific, and must be designed for the required temperatures and pressures. With the development of technology, the demands on lubricating oils have evolved and specialized. While older engines required better lubrication, modern engines with filter systems require residue-free burning oils. Certain oils are also specially designed for vehicles with high mileage.

Bestseller in Germany

► Castrol EDGE Advanced Full Synthetic Motor Oil – 5W30

► Motul 7100 Synthetic Ester Motor Oil – 10W40

► Liqui Moly Leichtlauf High Tech Engine Oil – 5W40

The Purpose of Engine Oil Filter

Oil filters keep the engine free of debris, soot, and the remnants of unburned fuel taken up by the engine oil. Thus, the cooperation of engine oil and oil filter prevents engine damage, and contributes to the performance of the engine. To maintain engine performance, it is therefore important that the engine oil remains clean and free of debris. As a result of increasing engine power and longer oil change intervals, the requirements for oil filters are also increasing.

The way an oil filter operates is relatively simple. The oil pump lets the engine oil flow through the outer holes into the filter. A gasket ring provides a constant seal of the filter to the engine. Inside the oil filter is the filter paper, which is folded for reasons of space, and thus can be installed as compact as possible. The paper is internally stabilized by a cylindrical plate. The bypass valve allows for pressure relief and enables the oil to get to the engine in case of contamination or clogging of the oil filter.

How to Change the Engine Oil

When should you change the engine oil?

The use of the vehicle contaminates the engine oil, which over time causes it to fail to adequately perform its important functions. For example, frequent cold starts can result in engine oil being diluted by unburned gasoline residues. At the same time, the additives which improve the friction characteristic of the engine oil are degraded over time. The engine parts, that are exposed to friction, have indeed generally hardened surfaces. However, once this hardened layer has rubbed off, further wear occurs very fast. Regular oil changes can prevent engine damage over the long term and extend the lifespan of the engine. At what intervals the engine oil has to be changed depends on various factors. Here, the general condition of the engine, and the accuracy of processes such as injection and ignition play an important role. As an indicator for a low oil pressure, the driver is informed about the warning light in the dashboard. This can be due to a low oil level or caused by a defective oil pump.

☞ As a common guideline it is recommended to change the engine oil every 10.000 to 20.000 miles. This is usually the case every one to two years. Depending on the engine, it may also be due after 50.000 miles. In addition, you should always check the oil level after 1.000 miles.

If drops of water form on the dipstick, this usually indicates that cooling water has entered the oil. In that case, you should check the cooling water next. If oil is visible in it, it indicates a defective cylinder head gasket. Alternatively, it can also be just condensation.

Changing the Engine Oil by Yourself

A simple oil change can always be carried out in any car workshop. But in a few steps, you can also do the the whole process by yourself. All you need is the right tool for opening the drain plug and a container for the old oil.

Before performing the oil change, you should run the engine for about 3 minutes so that the existing oil in the engine absorbs the deposited dirt particles. Then you open the oil cap on the engine and lift the car to get better access to the bottom of the vehicle. Now you should put a container under the car, and open the oil drain plug of the oil tank. Since the oil is still hot, you should be careful. After all the oil has drained into the container, wipe the bottom of the vehicle and close the oil drain plug again. Now you can fill in the new engine oil. In doing so, you should pay attention to the amount of oil specified by the manufacturer and measure the oil level in between.

☞ It is advisable to record the date and the mileage for the oil change made.

Engine Oil Flush

There are many different opinions on engine oil flushing. While some are convinced of the positive effects, others consider it completely redundant and sometimes even harmful to the car. In contrast to conventional engine cleaning, where you clean the outer part of the engine unit, an engine flush cleans the inner parts. For this purpose, special additives with a cleaning effect are added to the engine oil, which are distributed within a few minutes with the oil circuit throughout the engine. In order for the additives to develop their cleaning effect, the engine must be idling for a few minutes. During the cleaning process, the dirt in the engine is loosened and at the same time prevented from settling back on other areas of the engine. Afterwards, the old oil with the cleaning additive and the removed dirt is drained from the engine, and new oil can be topped up.

Modern engine oils contain small amounts of cleansing additives, so an engine oil flush is rarely needed. In older cars, it may make sense, since older engine oils can not remove some residues that accumulate in the engine over time.

How to Change the Oil Filter

For every oil change, it is also recommended to replace the oil filter. For different cars, the oil filter can be mounted in different places. To change the filter you need next to the conventional utensils for an oil change hardly additional tools. In some cases, it may be beneficial to use a suitable wrench head for unscrewing the oil filter housing.

Before you get to work you should let the engine run for a while so that the oil resumes the accumulated dirt particles. After about 3 minutes, the oil should have flowed through the engine well and be ready. Then you turn off the engine, open the lid for the oil filling and lift the car with a jack, or drive it on a lift. After putting a suitable container under the vehicle you can open the oil drain plug and let the worn out oil flow out. Only after the entire oil has run out of the engine can you remove the old oil filter. It should be noted that this is also filled with engine oil, so you should put a container under it before the removal. Use a suitable tool and loosen the filter together with the sealing ring. So that no further oil gets into the environment you can put the old parts in a plastic bag.

Now you should fill the new oil filter partly with oil, so that the oil supply is ready immediately at the next engine start. With a brush you can also lubricate some fresh oil onto the gasket of the new filter before mounting it to the car. After you have installed it together with the gasket ring onto its place you can refill the oil level. Now you should let the engine run again briefly, and if necessary correct the oil level again.

☞ If you want to learn more about filtration systems, you can read our article: Filter Systems in Cars

Which Engine Oil is Best?

Not every car can handle any oil. Therefore, it is important in the first place to follow the recommendations of the manufacturers, which can be found in the owners manual of the vehicle. In general, the approvals of the vehicle manufacturers can be also found on the engine oil tank in addition to the European and American standards. Especially with newer cars motorists should always pay attention to whether the label of the engine oil contains a release for the respective car. The specifications of many car manufacturers are also similar, so that many high-quality oils can be used simultaneously in several different vehicle brands. It is important to know that engine damage caused by the use of incorrect oil is not covered by the manufacturer’s warranty and is also rejected by car insurance companies.

Above we looked at some of the best engine oils available on the market and worked out our list for you. Keep in mind, however, that the listed products cover only certain classes, and our recommendations are therefore more focused on common usage. In general, 5W30 engine oils have the most demanded viscosity grade among car oils. Ultimately, there is no universally best engine oil in the world, and different oils can therefore be better suited for a specific engine or special conditions of use.

☞ You should be careful with unknown brands that are offered on the Internet, as often questionable oils are offered with false manufacturer releases. The oils listed by us are therefore all from renowned manufacturers who are known for their quality.

Bestseller in the US

► Mobil 1 Advanced Full Synthetic Motor Oil – 0W20

► Pennzoil Ultra Platinum Full Synthetic Motor Oil – 5W30

► Valvoline MaxLife High Mileage Motor Oil – 5W30

For customers in America the starburst icon a trustful sign to choose from. It indicates that the oil was tested and meets the requirements of the American Petroleum Institute (API). The institute subdivides the types of oil according to engine type and performance level.

(image: api.org)

The ACEA (European Automobile Manufacturers Association) divides engine oils into four classes A, B, C and E.

A – gasoline engines in passenger cars

B – diesel engines in passenger cars and light commercial vehicles

C – diesel engines with particle filter

E – diesel engines in commercial vehicles and trucks



In Asia, the associations ILSAC, JASO and JAMA are in the foreground.

☞ Engine oil basically consists of two components: base oil and additives.

Engine Oil for Diesel

The right engine oil depends primarily on whether you have a gasoline or diesel engine. A diesel engine requires a different engine oil than a gasoline engine because, among many other aspects, the combustion temperature is different. In diesel engines, combustion produces significantly more soot particles that accumulate on the engine. These are absorbed by the oil. As a result, the color of the engine oil changes faster in diesel engines than in gasoline engines. A dark color of the oil is therefore not necessarily a sign of a due oil change in diesel engines.

Engine oil for diesel with particulate filter

Diesel particulate filters retain harmful carcinogenic soot particles from the diesel exhaust gases. In addition to soot, remnants of burned engine oil also remain in the filter, which can be a problem there. The residues are mainly formed by the additives that are added to the oils to optimize performance. Unfortunately they sometimes end up in the combustion chamber, and become ashes after their combustion. Since a part of the engine oil always enters the combustion chamber of the engine, the formation of these ashes can not be prevented. The solution to this is provided by specially designed additives that burn with little residue and form as little ash as possible. It is ensured that they have low levels of sulfate ash, phosphorus and sulfur to prevent the particulate filter from clogging.

Engine Oil for Motorcycles

An engine oil for motorcycles differs in principle hardly from conventional oils for cars. However, many motorcycles have a single oil circuit for the transmission and the engine, so the oil is subject to other requirements. Since the same oil, which is responsible for the engine lubrication, must withstand the high pressures in the transmission, it is equipped with additional additives. These allow the oil to fulfill both tasks simultaneously, and to withstand the load on the gear wheels.

Wet clutches are widely used in motorcycles and dirst bikes, and run with the lubrication of engine oil. This is not the case with a dry clutch. However, wet clutches do not tolerate the additives contained in engine oils intended for cars. While the additives in cars provide for a more economical fuel consumption, they reduce the coefficient of friction for the motorcycle clutch.

Viscosity

Viscosity refers to the flow resistance of a liquid, which is an important feature of motor oils. Low viscosity oils spread faster in the foreseen areas of the engine, reaching all corners. In contrast, engine oils with high viscosity can apply a thicker oil film. Different engines prefer one or the other, depending on the concept. Especially for high-performance engines, it is important that the lubricating film does not break at high speeds and temperatures. The viscosity of the oil also changes with rising temperature, which is why multi-grade synthetic engine oils have been developed.

☞ The ‘W’ in the viscosity designation stands for winter oil. The indication ranges from 0 to 25, and indicates up to which temperature the engine oil remains liquid.

0W – to minus 30 ° C

5W – to minus 25 ° C

15W – to minus 10 ° C

25W – to minus 5 ° C

☞ The number behind the W, on the other hand, is an indicator of heat suitability.

Popular Viscosity Grades for Car Engine Oils

5W30

The 5w-30 covers a wide temperature range and is recommended by many manufacturers. The oil is thin and keeps consumption low. It has gentle properties for cold starts, and can be used up to high temperatures. Synthetic 5w30 engine oils are considered to be especially pure and of good quality.

☞ Our recommendations: Valvoline 5W-30 MaxLife , Castrol EDGE 5W-30

5W40

The oil is more viscous than the 5W30 and has a more stable consistency. This oil variant ensures less wear on the engine and generally has higher operational safety. This leads to a slightly higher resistance in the engine, which results in slightly higher fuel consumption.

☞ Our recommendation: Shell ROTELLA T6 5W-40 Engine Oil

10W40

0W30

This grade of engine oil has a low viscosity and can result in more efficient fuel consumption because it reduces friction in the engine. At the same time it’s the best engine oil to protect the engine in a cold weather environment. It can contribute to the longevity of the engine by protecting it against the negative effects of frequent cold starts.

☞ Our recommendation: Castrol EDGE 0W-30 Full Synthetic Motor Oil

5W30 longlife

Longlife engine oils are fully synthetic low-viscosity oils used in vehicles with computer-calculated longlife service. A 5w30 longlife lasts longer than a normal 5w30 engine oil, and has therefore longer service intervals . Due to the warranty conditions, among other things, they must not be supplemented or filled with other motor oils. A vehicle designed for Longlife service can also be run on standard engine oil. For this, the changeover in the engine control unit must also be set. The disadvantage of longlife engine oils is that, due to their longer maintenance intervals, the oil filters are changed less frequently.

Mineral Oil vs Synthetic Engine Oil

Both mineral oil and synthetic oil are derived from petroleum. The production of mineral oil is cheaper, which is reflected in the lower price. Synthetic engine oils are chemically improved in their properties, and designed for specific needs. In principle, they are therefore used in high-performance engines. Due to their improved quality, synthetic engine oils can also last longer between oil change intervals. For moderate driving on the road, the use of mineral oil is usually sufficient.

The advantages of synthetic engine oils are:

– better cold start of the engine at low temperatures

– the lubricating property can withstand higher load and temperatures

– less wear due to faster lubrication

– under certain circumstances lower fuel consumption

☞ The use of old oils with simpler compositions may cause problems in newer vehicles. Conversely, the engines of vintage cars can sometimes not handle modern synthetic engine oils.

Best Engine Oil for the Winter

In winter, engine oil is of particular importance. As the temperature decreases, oil becomes increasingly viscous. Modern cars prefer synthetic oil, which, while having better winter properties than normal mineral oil, is nevertheless compromised under cold weather conditions. That’s why you should still be careful with modern engines after the cold start, and try not to burden the engine on the first few miles. Only after the engine oil has warmed up, higher engine speeds can no longer have any negative influence on engine performance.

High quality synthetic engine oils are able to retain their viscosity even at low temperatures, allowing them to be pumped quickly through the engine and to all potential friction points. It used to be customary to use different engine oil depending on the season. In winter, for example, you would have switched to something like 10W-30 oil or vice versa in the summer to 10W-40. Today, with the development of multi-grade synthetic motor oils with polymers, it is possible to use the same level of viscosity throughout the year. These synthetic oils are based on low-viscosity oils and contain special additives that ensure that their viscosity only slightly decreases at higher temperatures. For example, engine oil with the 0W-40 viscosity class can be used without problems in the cold winter at minus 30 degrees, and also in summer. This was previously not possible with the single-grade engine oils that were used by the broad masses until the 1970s.

☞ The exact temperature ranges of the individual viscosity classes can be found a little further up under ‘Viscosity’.

High Oil Consumption

It is initially normal for a car to consume engine oil. The normal oil consumption is usually due to the fact that some of the engine oil gets into the combustion chamber and burns there. In older engines, the oil consumption can generally be slightly higher. However, it becomes problematic if the oil consumption is too high, which not only causes additional costs, but also pollutes the environment. If you notice a low oil level, it is advisable to top up the engine oil immediately. It is not recommended to drive the car with low oil. The reasons for increased oil consumption can be anything from normal wear to serious technical problems.

Engines with turbochargers consume more oil than naturally aspirated engines due to the lubrication of the supercharger turbines. At the same time, turbochargers can also be the reason for a further increased oil consumption if the bearings are not tight. In this case, the engine oil can be sucked through the turbine and conveyed with the charge air to the combustion chamber.

Wear on the cylinder, the cylinder heads, the piston rings or valve stem seals also increases oil consumption because (as in almost every case) the engine oil gets into the combustion chamber.

The driving style also has an effect on the oil consumption, since more heavily loaded engines are exposed to higher pressures. In addition, the engine temperature causes a lower viscosity of the oil, which in turn allows more engine oil to pass through the seals into the combustion chamber.

Oil Consumption of Diesel Engines

In diesel vehicles, the oil consumption is usually slightly higher than in cars with comparable gasoline engines. This is normal and should not cause any concern as long as it is below the manufacturer’s limit. The cause of excessive oil consumption in a diesel engine could, for example, occur due to the seals or the injection pump. Even the combustion process can lead to an increased oil consumption. With a regular and professional maintenance you can usually prevent these types of problems.

Engine Oil Stop Leak

An Engine Oil Stop Leak is an additive that is added to the oil to aid the seals in the engine and reduce oil consumption. It can usually be used with all commercial motor oils in gasoline and diesel engines, and develops its sealing effect after about 600-700 Kilometers (around 400 miles). If oil loss occurs due to time-hardened gaskets, it can be effectively remedied by using Engine Oil Stop Leak. The oil loss at unnoticeable small leaks is prevented, and the engine seals made of rubber or plastic such as shaft seals or valve stem seals are regenerated. The rubber parts are lubricated and remain elastic, which also extends their life. In addition, existing engine noise caused by oil loss is reduced, and oil stains on the underside of the vehicle which harm the environment are prevented. Modern products are neutral to catalysts and have no negative impact on oil quality or viscosity.

☞ An Engine Oil Stop Leak does not repair any mechanical damage, but can be very helpful in case of oil loss. The regeneration process of the seals takes about 8-14 days, or up to 400 miles depending on how the vehicle is used. If there is still no improvement, then the cause of the oil loss is probably due to a mechanical defect.

The Best Engine Oil Additives

In addition to the additives already used by the manufacturers, additional additives can be added to the engine oil. These are designed for different functions and load requirements of the engine, and change the properties of the engine oil accordingly. About their effect, and whether it makes sense to use them, there are different opinions. On the part of engine oil manufacturers, most additives are declared superfluous. Even many automakers advise against mixing additional products into the oil. Nevertheless, there are many users who are convinced of their positive results.

Our opinion is that in some cases the use of additives makes sense, as it can improve the properties of the engine oil to a specific function. For a specific fault on the vehicle, which is not covered by the commercial mass products, this can definitely be helpful. Nevertheless, you should inform yourself in advance about the respective additive in order to avoid possible side effects.

☞ The disadvantage of subsequently added oil additives is that you can not say exactly how the effect will unfold with the particular engine oil. For this reason, we unfortunately have no list of the best engine oil additives for you. A popular additive is, for example, the ‘engine oil stop leak’. Its positive effect against oil loss has been proven in many tests.

Mixing Engine Oils

Actually engine oils should not be mixed together. If the manufacturer prescribes a specific engine oil for your vehicle, you should not add any other oil to it, otherwise it will affect the warranty in case of an engine failure. However, it is in principle possible to mix oils that are designed for one and the same engine type. For example, you can easily mix a 5w30 with a 5w40 engine oil, as long as you stick to the engine approvals. But you should avoid mixing the oil for a diesel engine with that of a gasoline engine, because that would affect the engine-specific properties. Engine oil should also never be mixed with gear oil or other oils. Also, mixing mineral oil with synthetic or semi-synthetic oil might alter the properties of the engine oil. Technically, oils can not form a harmful composition for the engine by their mixture. Nevertheless, it is not recommended in some cases.

☞ It is better to give the engine a mixed oil than to drive it with too little oil.

Storage of Engine Oil

To ensure that your engine oil remains usable for as long as possible and retains all of its intended properties, proper storage is important. Synthetic engine oil tends to age more slowly than mineral oil because it has a beneficial composition of oil molecules in addition to the additives it contains. The molecules of synthetic oil are more uniform on the surface of the oil, so that oxygen has less impact on it. But even the best engine oil can lose its favorable properties due to external influences and cause damage to the engine. Synthetic engine oils, for example, separate the antioxidant additives and lose their properties over time. In order not to accelerate the aging process, you should therefore make sure that the container is well sealed, and no dirt or moisture can get into the oil. One should also consider that already opened engine oil is not as durable as sealed. Therefore, already opened container should not be stored for more than half a year. Likewise, leakage of engine oil is one of the key points that should be avoided during storage. An oil puddle in the garage or in the basement can significantly increase the risk of fire. Old and expired engine oil can usually be disposed of at gas stations.

A gasoline or diesel engine consists of many hundreds of moving parts, all of which have precisely defined tasks and characteristics. Many of these components press and rub against each other. That would quickly lead to great damage without proper lubrication.