What is the Best Synthetic Oil?

Finding the best synthetic motor oil for your car or motorcycle can be tough. I have put together this resource to help you find the best synthetic oil and with my experience will help you make an informed decision on what to use next or confirm that you may already be using the best.

As you know, there are just so many brands, companies, colleagues and friends making marketing, technical and personal claims out there that they promote, sell or use. Of course, behind all that gloss, it’s only about sales & profits – or is it?

Nowadays, mainly yes is my observation of a lot of the hype. However, historically synthetic oils and fuels were originally developed to manage extreme conditions or situations that conventional mineral oil based products could not.

Synthetic Oil Background

In the 1940’s, WWII situation led to the research and development of fully synthetic gasoline. In the 1960’s, the conditions of jet aircraft aviation turbine engines and extremes of temperature led to synthetic jet engine oils still exclusively used I understand in almost every jet engine in almost every aircraft to this day.

Then, into the 1970’s & 1980’s space travel, more synthetic oil technology in industrial oils and greases. In the 2000’s, look at wind turbines as an example.

So, back in the 1970’s, some oil companies started to market synthetic engine oils promoting this new technology to everyone.

For Techo’s, great, for Marketers, hard to sell. Techo’s promoted extended oil changes, turbocharger protection, extreme low temperature & high temperature performance, fuel economy, motor protection etc.

For the Marketer, synthetic oils were expensive costing up to 5 times the cost of conventional mineral oils so a specific and relatively very small market – and they were right. They focused on high technology car racing and audience such as NASCAR and Formula 1.

That is until the governments, environmentalists and engine manufactures all over the Globe started to initiate, develop or be forced into improving fuel economy, reducing exhaust emissions and extending oil drains during the 1980’s and 1990’s. All this presented the biggest challenge to engine oil technology that is ongoing today!

Synthetic oils were no longer just for NASCAR and Formula 1, but for everyone from car manufacturers to do-it-yourselfers at home.

What is Synthetic Oil?

Did you know that 80-90% of an engine oil is Base Stock? The rest is made up of Additives. So to be the best synthetic, you would think you would need to have the best synthetic base stock as a start.

HVI PAO Image - best synthetic oil

Particularly PolyAlphaOlefins (PAO – Group IV), Esters and utilization of Alkylated Naphthalene’s. (Group V). These were the original synthetic base stocks as tailor made from building blocks using chemical processes to create the “perfect” oil molecule.

However, hydrocracked base stocks (Group III) can nowadays also be marketed as synthetic but are still mineral oil based.

Group I and II base stocks are Conventional Mineral Oils manufactured by Solvent Refining or Hydrotreating. I hope that these are not marketed as synthetic by anyone?

The performance advantages of synthetic base stocks, particularly PAO’s, are numerous and overwhelming. I believe that the perfect oil molecule is an iso-paraffin ==> PAO.


"Nothing I’ve seen nor researched to-date has surpassed PAO for all Viscosity Grades, but what also convinces me is that all latest technology tries to “copy” PAO. What do they say, …”copying is the highest form of flattery”… maybe this is also technically true? This introduces the Techo and Marketing dilemma as PAO is much more expensive to make!"

Now, what about the other 10-20%, the Additives? This is also very important and very complex.

Additives are needed to enhance the performance of the Base Stocks. Some engine oils contain an Additive Package you can buy “off-the-shelf” and mix with your Base Stocks. This works. But I believe the best use component additive chemistry researching, developing and testing to find the most optimized, balanced and synergistic formula.

Did you know?

Did you know that 80-90% of an engine oil is Base Stock? The rest is made up of Additives.

The best engine oil may therefore be a very complicated blend of synthetic base stocks and over a dozen maybe up to twenty component additives!

It’s sort of like buying a frozen meal to reheat in the microwave back home that is going to taste good, inexpensive and saves time – but if you want the best, you have to find all the individual ingredients and cook it yourself!

Yes, it does take more time, some experimentation and maybe more expensive – but was that the best meal you ever had?

Even better when you use your homegrown food!

Most, if not all, engine oil marketers do not disclose their formulas for proprietary reasons. This is obvious with all the variations available to them and the “technical versus marketing” claims over synthetic.

This makes yours and my job extremely difficult – what Base Stocks are they using if they don’t tell you?

So, I will stick with those that I believe still use Group IV (PAO) & Group V (Esters/AN).

I exclude Group III as believe technically they are basically the same as Conventional Group I & II Base Stocks in engine oils. Even I am in discussion over the latest technology of GTL (Gas to Liquid) Base Stocks. I believe that are classified as Group III+

best synthetic oil

Why use Synthetic Oil?

The benefits of synthetic oil are numerous and overwhelming because Synthetic Base Stocks i.e. PAO’s, Esters & AN are tailor made from molecular building blocks using pure ingredients so do not contain any of the impurities found in crude oils that end up in Conventional Mineral Oils.

Let’s summarize a few benefits:

  • They have a naturally very high viscosity index, which means they do not require any or anywhere near as much additives that can break down in your engine that significantly changes your new oil as soon as you turn the ignition key! Yes, many engine oils can change as soon as you crank over that engine from your fresh oil change! So you thought you bought ”thick” oil?
  • Because they have no impurities like wax, yes the same as in a candle, they have excellent low temperature fluidity and are much thinner at very cold temperatures. This means your engine oil flows immediately you start up in very cold conditions and this is just so important for minimizing engine wear and getting you going.
  • Rather than having hundreds of different hydrocarbons, synthetic base stocks are basically pure with just a few. So by not having a whole stack of lightweight hydrocarbons that will “boil off” from a mineral oil, volatility is very low. This is just great for reducing oil consumption and emissions to the atmosphere!
  • With no impurities such as unstable hydrocarbons in mineral oil that remain from the crude oil, there is not much to oxidize so they have good oxidative stability meaning much less deposits, as the oil basically does not break down.
  • They also have good thermal stability so as the temperatures keeps arising in your engine, the oil stays the same.
  • As being pure and tailor made, synthetic oils provide low traction force, which means less friction therefore reducing fuel consumption or increasing your horsepower!
  • They are compatible with all engine oils – so you can start to use now!

The Best Synthetic Motor Oils

Oil is the life blood of a car or motorcycle’s engine, keeping moving parts in the best condition possible so it can reach maximum potential. Synthetic motor oils are preferred by many auto and motorcycle manufacturers and owners over old fashioned conventional oil.

It provides better engine performance, longer periods of time between oil changes, and overall better efficiency and environmental soundness.

One of the most important decisions a car owner can make is to choose the best synthetic oil for the particular engine. This includes the right motorcycle oil for the needs of those specialized engines.

Unfortunately, most people don’t make an educated choice for the oil used in their car, but rather accept whatever the technician or garage offers in a cheap oil change or for an oil change coupon.

The better alternative is to use an oil change provider that will allow you to choose your oil, or do the change yourself.

After doing your research and choosing the best synthetic motor oil, you will then be better equipped to make the right choice for maximum performance from your car.

#5 Castrol

This brand, now owned by British Petroleum (BP) is one of the better marketers to the high performance throne.

Castrol really focus on “additives” and from “Syntec” are now starting to promote “Titanium”.

Remember “Magnetic”, then “Syntec” now “Titanium”.

They must buy their Base Oils if PAO Group IV or Group V.

Castrol is popular amongst racing teams and car manufacturers, and offers higher performance than mid-range synthetic motor oils, while still being slightly less expensive than the top of the line oils.

best synthetic oil

Castrol EDGE Synthetic Motor Oil

#4 Pennzoil

With its proprietary PurePlus™ formula, Pennzoil Platinum synthetic motor oils convert natural gas into a mixture that creates cleaner pistons and a smoother functioning engine is their claim.

So, they at least share what Base Stocks they use, Group III, not Group IV, so can claim “synthetic” but also focus a lot on additive technology.

They buy their base stocks so are benders so not sure why they claim they do it?

best synthetic oil

Pennzoil Platinum Full Synthetic Motor Oil 

#3 Royal Purple

Very interesting as they market both API Performance products and others that should only be used after your car/engine warranty has expired.

Why for the latter?

Because they increase the antiwear additive content above the requirement for control of exhaust emissions when new!

So, if you have an older car and don’t mind maybe increasing your emissions then go for the Fully Synthetic Base Oil options as you’ll still get all the other benefits.

best synthetic oil

Royal Purple High Performance Synthetic Motor Oil

#2 Amsoil

Makes the claim of being the first to market Full Synthetic Engine Oil.

Not sure, but still believe they buy all their Base Stocks and then blend with purchased additives?

So, if they utilise Group IV PAO plus maybe some Group V in their products, gotta be a great oil with their experience!

#1 Mobil 1

Mobil is the only oil company and brand that I know that has been involved in the research, development, manufacture and marketing of synthetic base stock and synthetic oils since the 1960’s to this day.

They actually make all the different types of base stocks covering Group I, II, III, IV & V from Conventional Mineral to Synthetic.

I believe the Mobil 1 family is the best synthetic oil as this is what Mobil have been doing for over 40 years – sort of “homegrown” synthetic engine oil!

Many other brands are companies that buy base oils and technology and then resell!

Also, did you know that PAO’s from Mobil are so clean that they can be classified as Technical White Oil for Incidental Food Contact with both Kosher and Halal approvals?

best synthetic oil

Mobil 1 Synthetic Motor Oil

For those fortunate enough to fly domestically or internationally, look out the window as most of the aviation turbine engines in the world are lubricated by Fully Synthetic Mobil Jet Oil.

Mobil oil is the best known and most popular motor and motorcycle oil. Widely considered the best synthetic oil by many owners and experts in the industry, Mobil oil has been road and manufacturer tested across many platforms, conditions, models, and years.

Porsche stress tests have shown extreme engine wear protection, Mercedes “Million Kilometer Test” has demonstrated how clean Mobil 1 is the best synthetic oil to operate in the toughest “real-world” driving conditions, resisting “sludge and deposit formation” to keep the oil looking like new.

Did you know?

Did you know that PAO’s from Mobil are so clean that they can be classified as Technical White Oil for Incidental Food Contact with both Kosher and Halal approvals?

Mobil 1 oil has also been proven to operate in the most extreme weather conditions: the heat of the Las Vegas strip, and even the cold of the arctic circle. Mobil 1 is also the preferred high performance oil of many professional race teams and manufacturers. More than half of all NASCAR teams choose it. Many automakers choose it for factory fill and it has received more automaker and industry approvals.

As for cons of using Mobil 1, most customers report only cost as a negative. Mobil 1 is a bit higher in price than most others, but they usually say that it’s well worth the few extra dollars.

Pouring Motor Oil Image

Synthetic Oils for Better Protection

Since synthetic oils last for so long between required changes, problems in the engine may go unrecognized for many miles. It is important to open the hood and check underneath on a frequent basis, even when you are not changing the oil.

The one downside of using full synthetic oil is the price. It can be quite expensive. If the synthetic engine oil is based on PAO and not semi- or part-synthetic then it is pure and will cost more.

However, PAO combined with great additive chemistry, you have an oil that will virtually keep your engine like new!

Full protection does cost more at each oil change, but in the longer run, it could actually work out cheaper – particularly if you extend the oil drain period!

While there are many quality synthetic motor oils on the market, Mobil 1 is most widely considered to be the best synthetic motor oil around. With careful shopping, this premium product can be in a cheap oil change, or covered by an oil change coupon.

If you are still deciding between regular, synthetic, and synthetic blend oil, view the following infographic to learn more about each type.

Your content here...

The Ins and Outs of Engine Oil Types

From Visually.


​Choosing the best synthetic motor oil for your car will result in great benefits, higher performance. If you use a fully synthetic motor oil, you can double/triple the oil drain/change period for your car. This means not only less cost in the long run, you use & dispose of 50% less oil!

In addition, if the fully synthetic motor oil keeps your engine like new then your exhaust emissions are also relatively reduced – now that’s good for the environment! Read all the information we have put together and you can see that choosing the right synthetic motor oil could be the very best investment you’ve ever made! Love to hear your thoughts. Please feel free to leave a comment or ask any questions in the comment section below. Thanks for reading!


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Gary is the Technical Author and retired in 2011 after almost 39 years in the oil industry. He has been involved with Oil Industry Associations, Engine and Equipment Builders, Automotive Manufacturers, Racing Teams and Customers. Specializing in Automotive Engine Oils. He has worked in and visited countries and markets all over the Globe. His knowledge and experience will help you choose the best synthetic oil.

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