The Best Car Oil Guide: How to Find the Best Oil for your Car

The Best Car Oil Guide: How to Find the Best Oil for your Car

Did you just get a new vehicle and you’re not sure how to find the best engine oil for your car? With so many different options on the market, this quest can get quite complicated, even though determining which engine oil the car manufacturer recommends is easy. All car manuals include engine oil recommendations, so if you are in doubt about which engine oil you should use, simply read the car manufacturer’s instructions.

Although acquiring information about which engine oil you should use for your car is a straightforward process, knowing a thing or two about engine oils can come in handy in a broad range of situations. Information about the oil’s viscosity or whether the oil is meant for petroleum or diesel engines can make it easier for you to select a product that will enhance your car’s performance.

That’s why in this guide we are going to take you through all of the most important aspects of engine oils and help you gather all the information you need to find the best oil for your car.

Up Front Best Car Oil

  1. Mobile1 Extended Performance: Best Overall
  2. Castrol GTX Synthetic Blend: Best Semi-Synthetic Engine Oil
  3. Valvoline Premium Conventional: Protects All Parts of The Engine

My Top Pick
Mobil Extended Performance | Advance Auto Parts

There are several car oils that can really help enhance your car's performance. The Mobil Extended Performance really stands out. It improves your cars fuel economy and helps expand your engine's life.

Check Price Buy at
We earn a commission if you click this link and make a purchase at no additional cost to you.

Why is engine oil so important?

engine oil

Lubrication and cooling are the most important reasons why cars can’t run without engine oil. The oil you add to a car engine provides lubrication for the engine’s internal parts and prevents the moving parts from grinding against each other. Furthermore, a certain amount of oil alongside fuel enters the combustion chamber, each time the piston reaches the engine’s top dead center. How much oil is going to be used in the process depends on the type of engine your car has and your style of driving.

Besides lubricating the engine, oil also lubricates the exhaust valves. This area of the vehicle can get extremely hot, which is the reason why a portion of engine oil that reaches the valves can evaporate in time. So, it is easy to see why cars and all other motor vehicles can’t operate without engine oil.

The dirt and sludge that accumulates in the engine can cause significant damage to it and dirty oil is not as efficient in lubricating the engine’s moving parts as fresh oil. That is the reason why regular oil changes are mandatory if you want to keep your car running properly.

How frequently you have to change the engine oil depends on the type of vehicle you have, but most car manufacturers recommend oil changes after 3,000 to 5,000 miles. Changing the engine oil isn’t difficult at all, so you can either do it on your own or you can go to the nearest lube shop and have a professional do the job for you.

What are the most common types of engine oils?

The debate about which engine oil produces the best results lasts for decades. Some car industry professionals claim that conventional, organic oils bring solid performance at a lower price. Others say that synthetic oils protect the engine more than conventional oils and that they improve the fuel economy.

Besides these two types of engine oils, you can also opt for synthetic blend oils that combine the best of the two worlds. Let’s take a look at what each of the most common types of engine oils has to offer.

Fully synthetic oils

As their name indicates, fully synthetic oils are made of artificial ingredients. The petroleum that is used to produce synthetic lubricants is chemically modified, unlike the crude oil that is used to produce conventional oils.

In order to determine whether an engine oil you would like to purchase is a fully synthetic oil you just have to check its SAE rating. Fully synthetic oils have 5W-40, OW-40 or OW-30 SAE ratings, which enables to easily find out if the oil is fully synthetic. The main benefits of fully synthetic oils are:

  • Improved fuel economy
  • Enhanced engine performance
  • Protection against damage caused by the daily use of a vehicle
  • Reduced mineral deposit build-ups
  • It circulates quickly through the engine, even in cold weather
  • Less frequent oil changes
  • Better cold start performance

Other than being more expensive than other types of engine oils, fully synthetic oils don’t have many downsides, and you can hardly make a mistake if you decide to add them to your car’s engine.

Semi-synthetic oils

The semi-synthetic oils are somewhere in the middle of the road between fully-synthetic and conventional oils. These motor oils protect the engine efficiently but they can’t protect the engine as fast as a fully-synthetic oil can. It takes about ten minutes for a semi-synthetic oil to protect the engine entirely, while with fully synthetics oils protection is provided almost immediately after you start the engine.

On the other hand, semi-synthetic oils do a much better job of preserving the engine than conventional oils and they allow you to cover more mileage between oil changes than the organic oils. They are a bit more expensive than conventional oils, although not as expensive as fully synthetic oils. The most common SAE rating for semi-synthetic oils are 15W-40, 5W-30 or 10W-40.

Conventional oils

This type of engine oil has the longest history in the auto industry, as some versions of it were used in the engines of the first mass-produced cars. Needless to say, modern conventional oils are very different than those produced at the beginning of the 20th century. They are made from a mixture of poly internal olefins, hydrocarbons, and polyalphaolefins.

Today, conventional oils are often used by car manufacturers to prepare the engine for fully or semi-synthetic oils. The engine protection they provide is only basic, and you should keep in mind that conventional oils don’t perform well in extremely cold or hot weather conditions.

Even though organic oils can be an affordable option for cars that don’t have complex engines, you must add fresh conventional oil to the engine after 3,000 miles. Most conventional oils you can find at gas stations have 10W-40 and 15W-40 SAE ratings.

Besides these types of oil, you can also opt for high-mileage engine oil that can be changed after 75.000 miles. Follow this link if you would like to find out more about high-mileage oils.

Read our full guide on how to find the best motor oil if you own a:

Is it safe to use diesel-rated engine oils on petrol engines?

The answer to this question was no for a long time, but the recent advancements in the auto industry have enabled drivers to add diesel-rated motor oils to petrol engines.

Currently, there are a number of engine oils that can be added to both petrol and diesel engines. However, there is a catch, because you must check if the diesel-rated engine oil meets all of the petrol engine’s specifications.

oil for engine

The diesel-rated engine oils often have higher SAE ratings, which means that you shouldn’t under any circumstances add engine oil for diesel engines to petroleum engines. Using the diesel-rated engine oils on petrol engines can cause significant damage, as they contain additives such as anti-foaming agents and detergents that are specific to diesel engines.  Click here if you would like to learn more about fuel additives for petrol engines.

If you don’t already know a lot about engine oils, it is best to avoid trying to add diesel-rated engine oil to a petrol engine, since it can prove to be a costly mistake that can potentially damage your car’s engine.

Do engine oils have expiration dates?

If kept properly, engine oils can be stored for up to five years. Even so, a certain level of precaution is advised if you are thinking about using an engine oil that is a few years old. New engines appear on the market at an astounding rate, and they rely on differently formulated engine oils to provide lubrication and cooling.

A two or three-year-old engine oil can be formulated differently than the oils a particular model of the car’s engine requires. This can be particularly important if you replaced your car recently, but you still have some engine oil that is leftover from your previous car. Engine oils that have a simple formulation commonly have longer shelf lives than those that have complex formulations.

Adding a freshly purchased engine oil that is recommended either by the car manufacturer or an auto mechanic is a much safer option since you won’t have to worry if the engine oil meets all of the engine’s specifications.

How much should I spend on engine oil?

Even the most expensive engine oils produced by well-known brands like Castrol, Valvoline or Mobile1 can be purchased for $50 or less. So, opting for higher-priced fully and semi-synthetic engine oils seems to be a reasonable solution, especially if you are using your vehicle to travel long distances.

These two types of engine oil let you cover more mileage before the next oil change, which makes them a more profitable investment than organic oils in the long run. Besides the less frequent oil changes, fully and semi-synthetic oils provide better protection of the engine’s internal parts, and reduce the amount of damage that occurs as a result of the daily use of a vehicle.

engine oil 1

If you don’t feel confident enough changing the oil by yourself, you should hire a professional auto mechanic to do it for you. This service can cost anywhere between $20 and $100, and you must consult with your mechanic about the best option for your car.

Most mechanics add extra services that help keep your car’s engine in pristine condition for longer periods of time if you decide to spend a bit more on the engine oil change. Additionally, having a professional check your engine at every oil change can potentially keep it in the optimal shape longer.

The Best Car Oil Guide: How to find the best engine oil for your car?

There are so many aspects to car maintenance, and using the best engine oil for your car is just one of them. Finding out which engine oil is recommended by the car manufacturer takes a minimum amount of effort since you just have to read the manual. If you do so, you’ll also learn how frequently you should check the oil level as well as the location of the oil gauge on the car’s engine.

Most car engines require differently formulated engine oils, so it is best not to experiment and just use the engine oil that is recommended by the manufacturer. If for whatever reason you decide to add a different type of engine oil to the engine you should first talk to a professional and find out if the oil you want to use can potentially damage the engine.

The SAE ratings and viscosity are the parameters you can find on all engine oil bottles and they indicate the type of oil and how efficiently an oil performs at high temperatures. Once you learn how to read the labels on engine oil bottles, you are going to be able to find if particular engine oil is the right fit for your car.

What is oil viscosity and how does it improve the engine’s performance?

Simply put, viscosity is a fluid’s resistance to flow, and you can find the viscosity designation on all engine oil bottles. Besides enabling you to find out the type of engine oil quickly, designations like 5W-30 or 5W-40 also allow you to check an oil’s viscosity.

The viscosity of all motor oils is tested at both zero and at 212 degrees Fahrenheit for their low and high-temperature performance. The number in front of the W indicates how well an engine oil is suited for cold weather conditions, while the number after W shows you if the oil performs well in hot weather conditions.

As the temperature rises, motor oils become thinner, while thickening occurs at low temperatures. Consequently, motor oils are rated differently for viscosities at high and low temperatures. The second number of the viscosity designation indicates the oil’s resistance to thinning, so the higher this number is, the better. Hence, if you would like to buy an engine oil doesn’t thin too much during summer you should opt for the oils whose viscosity is rated 40.

The number placed in front of the W show you if an engine oil can keep your engine safe during winter. For instance, engine oils with a 5W viscosity designation are often recommended to drivers who are driving in cold weather conditions. Keep in mind that some fully synthetic oils can be rated 0W, but you should only use them for extremely cold environments.

It is worth noting that you should under no circumstances use engine oil that has a viscosity rating that is different from the one recommended by the car manufacturer. Failing to do so can cause severe damage to the engine and cost you hundreds of dollars in reparations.

Understanding the SAE Ratings and the Viscosity Index

checking the oil

The SAE ratings indicate a motor oil’s viscosity grade that can help you determine if a particular oil is meant to be used in hot or cold weather conditions. These ratings are determined by the Society of Automotive Engineers and they are used to differentiate between monograde and multigrade oils.

 Most of the engine oils you can find on the market are multigrade oils because they contain grades for both low and high-temperature viscosity. The viscosity grades can fluctuate from 0W or 10W for engine oils that are formulated for low-temperature conditions to 70W or 75W for engine oils that can operate at high temperatures.

Besides the SAE viscosity grading, you should also pay attention to the viscosity index. The viscosity index is the number that is used as an indicator of an engine’s oil behavior at different temperatures. As the amount of heat to which engine oil is exposed to changes, so does its viscosity because the oil thickens or thins as the temperatures change. Moreover, factors like oxidation, pressure during operation or contamination can all influence an engine oil’s viscosity.

A low VI suggests that the oil’s viscosity is going to change significantly at different temperatures. Engine oils that have low VI indexes thicken when exposed to cold and turn thinner at high temperatures. Using an engine oil that has a low VI index is only advisable in climates where temperatures don’t vary throughout the year.

Furthermore, different types of engine oils have different viscosity indexes, so, for instance, a multigrade oil can have a VI that ranges between 140-200. Most of the engine oils you can find on the market perform well in both cold and warm weather conditions, and you can easily check their SAE ratings and viscosity index on the bottle. Low numbers in front of W indicate that the engine oil doesn’t thin at low temperatures, while the higher the number behind the W the better the engine oil can perform at high temperatures.

Should I use engine oil additives?

The vast majority of engine oils you can buy already contain a certain number of additives that fight corrosion or help clean the sludge build-up from the engine. However, these additives may not be enough to prevent the damage that occurs as the byproduct of the engine’s daily use. The most common types of fuel additives are:

  • Dispersants
  • Antiwear agents
  • Antioxidants
  • Corrosion inhibitors
  • Viscosity index improvers
  • Foam inhibitors
  • Detergents
  • Pour-point depressants

Each of these oil additives are used for a particular p0urpose, so, for example, you can use Antiwear agents to provide additional lubrication to the engine or add detergents to keep surfaces in the engine clean. It is worth noting that adding too much oil additives to the engine can damage it.

Antiwear agents contain sulfur that can make the catalytic converter less efficient and reduce the car’s gas mileage. Moreover, other engine oil additives can also impact a vehicle’s fuel economy, so before you start using them regularly you must consult with a professional in order to determine how much of oil additives you should add to the engine. Even though engine oil additives can help you increase the fuel economy or keep the engine clean, their extensive use can be counterproductive.

What are the best engine oil brands?

Opting for an unknown engine oil brand can be an ill-advised decision, that may potentially make your car’s engine less effective. That’s why sticking to the industry leaders like Mobile1, Valvoline or Castrol is probably the best option because each of these brands has a strong reputation for producing high-quality products. Moreover, these brands offer a wide variety of different engine oils, so even if you are looking for a low viscosity conventional oil, the chances are that you can find one that is produced by one of these brands.

Make sure to check the manufacturer’s oil engine viscosity specifications before adding the oil to the engine. Let’s take a look at some of the best engine oils produced by Valvoline, Castrol and Mobile1 brands.

Mobile1 Extended Performance

mobil 1

This is a fully synthetic oil formulated to provide thermal and oxidation stability to the engine. Like all fully synthetic oils, Mobile1 Extended Performance maintains the same viscosity at both high and low temperatures as indicated by the 5W-30 SAE rating.

It also extends the engine’s life and improves the vehicle’s fuel economy, enabling you to drive your car through different environments without causing any damage to any of its parts. Moreover, you can also choose from different versions of the product that have 0W-20, 5W-20 or 10W-30 SAE ratings, depending on how important the engine oil’s performance in cold weather conditions is to you.

My Top Pick
Mobil Extended Performance | Advance Auto Parts

There are several car oils that can really help enhance your car's performance. The Mobil Extended Performance really stands out. It improves your cars fuel economy and helps expand your engine's life.

Check Price Buy at
We earn a commission if you click this link and make a purchase at no additional cost to you.

Castrol GTX Synthetic Blend

castrol gtx

Car manufacturers like Land Rover, Audi or BMW recommend using engine oils produced by Castrol, which just shows you how highly regarded this brand is in the auto industry. Their GTX synthetic blend engine oil is no exception since it is probably one of the best semi-synthetic engine oils on the market. This is a high-mileage engine oil which means that you can replace it after every 75.000 miles.

The Castrol GTX synthetic blend reduces the chances of catalytic and emission system failure and it fights off sludge deposits effectively. It also improves the vehicle’s gas mileage and it is capable of high-end performances at both low and high temperatures. The best part is that you can choose between 5W-20 and 5W-30 configurations, and select the option that is better suited for your car’s engine.

Castrol GTX High Mileage Synthetic Blend Motor Oil | Advance Auto Parts

Castrol GTX High Mileage helps extend the life of your engine by protecting against sludge, wear and burn-off and is also engineered to protect your emission system against catalytic converter failure.

Check Price Buy at
We earn a commission if you click this link and make a purchase at no additional cost to you.

Valvoline Premium Conventional

valvoline premium

Organic oils may have their downsides but they are still powerful enough to provide lubrication to most engines. Valvoline Premium Conventional engine oil is designed to keep an engine clean and remove all deposits from an engine. It is also highly efficient at providing the anti-wear protection to vehicles that have gasoline and turbocharged engines.

The Valvoline’s engine oil also contains antiwear additives that decrease the thickening of the oil and protect all parts of the engine. So, if your car’s engine doesn’t need the extra protection offered by fully or semi-synthetic engine oils, then Valvoline Premium Convectional may be one of the best options on the market for you.

Even though each of these engine oils is capable of great performances you shouldn’t add them to your car’s engine before checking if using them can cause damage to the engine.

Valvoline Premium Conventional 5W-30 Motor Oil | Amazon

Valvoline Premium Conventional Motor Oil is specially formulated for the full life of the engine and comes in both multi-viscosity and mono-grade formulations. Multi-viscosity grades provide protection in all climates while mono-grade oils are formulated for warmer conditions.

Buy at
We earn a commission if you click this link and make a purchase at no additional cost to you.

How to find the best oil for your car?

Figuring out which engine oil is the best match for your car shouldn’t take too much of your time. If you just purchased a new car, its manual should provide you with all the information you are going to need in order to find if the oil that is going to keep all parts of the car’s engine lubricated at all times.

In case you are not happy with how the engine oil recommended for your vehicle is performing you should consider several different factors before selecting a new oil for your engine. How frequently you are using your vehicle, the climate of the area in which you are living, engine oil’s compatibility with your car’s engine or the cost of the oil changes can all be potentially important aspects that can help you decide which engine oil you should use.

The fully synthetic or semi-synthetic oils are more frequently used than organic oils, despite the price difference, because they have much more to offer. Car manufacturers often add conventional oils to their brand-new car models, but most car owners choose to switch to semi-synthetic or full-synthetic oils at the first engine oil change.

All of the biggest engine oil brands offer conventional oils that have different viscosities, so if your car doesn’t have a high-tech engine you can find an organic engine oil that matches your engine’s specifications easily.

Fully synthetic engine oils are made for powerful engines that are commonly featured on Mercedes Benz, Chevy and other high-performance vehicles. They are more efficient at removing deposits from the engine and they have higher viscosity ratings than any other types of engine oil you can find on the market. Fully synthetic oils are also more expensive than other types of engine oils, but investing in them can reduce the risk of damages considerably.

Semi-synthetic oils are a popular choice for SUV and pickup truck owners who are looking to improve their vehicle’s fuel economy. They are especially effective at high temperatures since they evaporate less than standard organic oils, which makes them perfectly suited for drivers who seek high-load protection. Which of these types of engine oil you are going to use, ultimately depends on the engine your car has. Using the wrong engine oil can prove to be a costly mistake that can damage your car’s engine permanently.

FAQ’s About Car Oil

In case you didn’t receive the manual with your new car, you should contact the car dealership where you purchased your car and request a manual. Optionally, you can also search for the instruction manual online.

Does engine oil remove dirt from the engine?

Yes, nearly all types of engine oils remove dirt from the engine, but their efficiency can vary.

How often should I change the engine oil?

Changing the engine oil at least once every three months is advisable if you are using the organic engine oil. If you are using semi or fully synthetic oils, oil changes can be less frequent.

How to check the oil SAE rating?

To check an engine oil’s SAE rating you simply have to look at its bottle. SAE ratings are usually placed at the very front of the bottle, so you can easily determine if the oil you are thinking of buying can perform well in different weather conditions.

Is it necessary to use a different type of engine oil during the winter?

No, it is not, especially if you choose a fully synthetic oil that doesn’t lose viscosity at low temperatures.


Taking proper care of your car is important for so many different reasons. Besides making you safer on the road regular car maintenance can make your journeys more enjoyable.

Choosing the best car engine oil for your vehicle can prolong the engine’s life, increase the fuel economy and keep the engine’s parts lubricated even in extreme weather conditions.

However, it is important to check the manufacturer’s recommendations or consult with a professional before you add new oil to your car’s engine. Which engine oil are you going to use? Leave a comment below and share your opinions with us.

My Top Pick
Mobil Extended Performance | Advance Auto Parts

There are several car oils that can really help enhance your car's performance. The Mobil Extended Performance really stands out. It improves your cars fuel economy and helps expand your engine's life.

Check Price Buy at
We earn a commission if you click this link and make a purchase at no additional cost to you.

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