12 Best Synthetic Oil Reviews 2018 – Buying Guide
Synthetic motor oils offer a lot of advantages when used in a car engine. From improved viscosity to the many other features that help to improve a car's engine life, lubricating your car's engine with synthetic oil is definitely a good idea.
Although some older vehicles may not gain much from synthetic oils, most modern vehicles from 2,000 on will definitely get a cleaner engine with less tear and wear, when they run on synthetic oil.
The issue with synthetic oils though is that there are so many of them in the market, including those that are no good and that's exactly where this review comes in.
You get a list of the best synthetic oils in the market, including how they measure up to one another, plus a buying guide to help you know what to watch out for when making your choice.
You can also read other product reviews such as 0W-20 synthetic oil, oil filter, fuel stabilizer, octane booster.
Contents
- 12 Best Synthetic Oil Reviews
- 1. Castrol 03101 Edge Full-Synthetic Motor Oil
- 2. Shell Rotella T6 Heavy-Duty Full Synthetic Oil
- 3. Pennzoil 5W-30 Platinum Full Synthetic Oil
- 4. Mobile 1 120769 5W-30 High Mileage Synthetic Engine Oil
- 5. Liqui Moly 2041 5W-40 Premium Synthetic Oil
- 6. Royal Purple 51530 5W-30 Synthetic Oil
- 7. Valvoline 782256 MaxLife Synthetic Motor Oil
- 8. Royal Purple 51520 SAE 5W-20 Synthetic Motor Oil
- 9. Valvoline 813460 SynPower Synthetic Motor Oil
- 10. Lucas Oil 10299 Magnum CJ-4 Synthetic Motor Oil
- 11. Mag 1 20139 Full Synthetic Oil
- 12. Honda GL1800 HP4S Synthetic Oil Package
- The Best Synthetic Oil Buying Guide
- When to Change Your Car's Engine Oil
- Conclusion
12 Best Synthetic Oil Reviews
Image | Product Name | Type | Vicosity | Volume | Rating | Current Price |
|---|---|---|---|---|---|---|
 | 1. Castrol 03101 Edge Full-Synthetic Motor Oil | Full Synthetic | 0W-40 | 1.25 Gal | 4.8 | |
 | 2. Shell Rotella T6 Heavy-Duty Full Synthetic Oil | Full Synthetic | 5W-40 | 1 Gal | 4.7 | |
 | 3. Pennzoil 5W-30 Platinum Full Synthetic Oil | Full Synthetic | 5W-30 | 0.25 Gal | 4.8 | |
 | 4. Mobile 1 120769 5W-30 High Mileage Synthetic Engine Oil | Full Synthetic | 5W-30 | 1.25 Gal | 4.8 | |
 | 5. Liqui Moly 2041 5W-40 Premium Synthetic Oil | Full Synthetic | 5W-40 | 1.30 Gal | 4.8 | |
 | 6. Royal Purple 51530 5W-30 Synthetic Oil | Synthetic Blend | 5W-30 | 1.25 Gal | 4.7 | |
 | 7. Valvoline 782256 MaxLife Synthetic Motor Oil | Synthetic Blend | 5W-30 | 1.25 Gal | 4.6 | |
 | 8. Royal Purple 51520 SAE 5W-20 Synthetic Motor Oil | Synthetic Blend | 5W-20 | 1.25 Gal | 4.7 | |
 | 9. Valvoline 813460 SynPower Synthetic Motor Oil | Full Synthetic | 0W-20 | 1.25 Gal | 4.8 | |
 | 10. Lucas Oil 10299 Magnum CJ-4 Synthetic Motor Oil | Synthetic Blend | 15W-40 | 1 Gal | 4.8 | |
 | 11. Mag 1 20139 Full Synthetic Oil | Full Synthetic | 0W-20 | 1.25 Gal | 4.8 | |
 | 12. Honda GL1800 HP4S Synthetic Oil Package | Full Synthetic | 10W-30 | 1 Gal | 4.3 |
1. Castrol 03101 Edge Full-Synthetic Motor Oil
Editor's Rating: 
(4.8 / 5)
- Type: Full Synthetic
- Viscosity: 0W-40
Castrol presents its most advanced engine oil formula here with the full synthetic Edge. It is a premium motor oil for the best engines with high-performance expectations.
This Castrol Edge comes recommended by many leading car manufacturers and it also meets the oil specifications of the largest car makers in the world, including Ford's WSS-M2C937-A specification and BMW's LL-01.
Some refer to it as the best full-synthetic oil that money can buy and Castrol guarantees that it's Titanium strong in reducing metal to metal contact and additionally protects your engine under extreme pressures.
This offer is for a 1.25-gallon container of Castrol's best synthetic motor oil brand, the Edge.
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2. Shell Rotella T6 Heavy-Duty Full Synthetic Oil
Editor's Rating: 
(4.7 / 5)
- Type: Full Synthetic
- Viscosity: 5W-40
Shell is a well-known brand in the motor fuel and oil industry and so a worthy contender when it comes to picking out the best synthetic oil brand. This Shell Rotella T6 formula offers lots of advantages over other engine oils.
Its low winter viscosity of W5 makes it very helpful in cold weather by improving engine startups and improving fuel economy up to 1.5% while maintaining enough viscosity to prevent wear and tear.
Another important feature is its low-ash technology. This helps in reducing the poisoning or blocking of devices that treat exhaust gases for emission control, such as the catalytic converter.
In addition to keeping good emission levels, the Shell Rotella T6 also features improved heat resistance, as well as advanced additive technology for protection against deposits, wear, and oil breakdown.
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3. Pennzoil 5W-30 Platinum Full Synthetic Oil
Editor's Rating: (4.8 / 5)
- Type: Full synthetic
- Viscosity: 5W-30
Designed to effectively clean out engine sludge better than most other oil brands, this full synthetic oil has premium active cleansing agents that help do the job.
It meets and exceeds the requirements of most car makers and is sure to offer the protection and cleaning that your engine needs.
As a top-rated synthetic oil, you can rely on its custom-designed features to offer the protection that your engine needs during periods of extreme driving conditions.
On the flip side, its price is for 1 quart and this makes it a little costly when compared with other oil offers, although Pennzoil also offers a six-pack of 1 and 5-quarts as well.
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4. Mobile 1 120769 5W-30 High Mileage Synthetic Engine Oil
Editor's Rating: (4.8 / 5)
- Type: Full synthetic
- Viscosity: 5W-30
High mileage oils are the best engine oils for vehicles that have crossed the 75,000 miles mark. The engines are different from those of other vehicles, so they need special care as well.
This Mobil High Mileage oil is specifically designed to cater for the needs of such high mileage vehicles by focusing on better wear protection and an increased level of seal conditioner to protect the engine's seals and prevent leaks.
It also offers your engine a high level of sludge reduction, although you'll need to change the oil in short intervals until the sludge is cleaned out or drastically reduced.
In addition to all these extra features for the high mileage engine, this oil also carries out its primary duty of lubricating and protecting the engine.
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5. Liqui Moly 2041 5W-40 Premium Synthetic Oil
Editor's Rating: (4.8 / 5)
- Type: Full Synthetic
- Viscosity: 5W-40
Designed for both gasoline and diesel vehicles, this motor oil from Liqui Moly comes from Germany and offers a 5W-40 viscosity. The brand name might seem unimpressive but the oil does have German qualities to it.
It provides a high and reliable level of lubrication at both high and low temperatures for both diesel and gasoline engines. It also helps in creating a high level of cleanliness in your engine.
All these features combine to give you an oil with a long service life that you can depend on because of its high level of protection against wear and its aging stability.
This oil fits many high-standard oil specifications, including BMW's Longlife-98, Porsche's A40, Mercedes Benz's 229.3 and the VAG 502 and 505.
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6. Royal Purple 51530 5W-30 Synthetic Oil
Editor's Rating: (4.7 / 5)
- Type: Synthetic blend
- Viscosity: 5W-30
Royal Purple offers a high-quality synthetic blend oil here and it goes a long way to show that a good synthetic oil doesn't have to only be fully synthetic.
The Royal Purple 51530 is a 5W-30 oil made from combining standard mineral oils with additives to give it an improved performance over ordinary mineral oils.
These improved features include protection from corrosion, protection of the car's emission control system, better protection from wear, and an improved fuel efficiency as a result of the improvement in lubrication.
This oil meets the Dexos1 and ILSAC GF-5 performance standards, although it's rather too costly for a synthetic blend package.
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7. Valvoline 782256 MaxLife Synthetic Motor Oil
Editor's Rating: 
(4.6 / 5)
- Type: Synthetic blend
- Viscosity: 5W-30
Older engines have different oil needs than newer engines. So, while other oils might offer you the best performance you can get, this oil was specifically designed to meet the needs of older engines.
Including Valvoline's MaxLife synthetic blend motor oil, this oil packs extra detergents to increase the cleaning action of your engine. It also comes with seal conditioners to rejuvenate old engine seals and help protect them from leaking.
You should note that this oil formula is not ideal for all engines. Your car would need to have clocked 75,000 miles at least before it can truly benefit from this oil.
In addition to extra detergents and seal conditioners, the oil also includes antioxidants and extra wear protection to cut down on future engine wear.
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8. Royal Purple 51520 SAE 5W-20 Synthetic Motor Oil
Editor's Rating: (4.7 / 5)
- Type: Synthetic blend
- Viscosity: 5W-20
Unlike the previous Royal Purple oil on this list, this one is strictly designed for gasoline engines and that's why it's also less viscous with is SAE 5W-20 rating.
Asides from viscosity, it features most of the other characteristics of a Royal Purple motor oil, including its ZDDP additives which help to protect your car's emission control system and its improved compatibility with ethanol.
It also features a high level of corrosion protection and better wear protection, which means less friction and better fuel efficiency. The only disadvantage of this only is that you can't use it in diesel engines, else it's great for petrol cars.
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9. Valvoline 813460 SynPower Synthetic Motor Oil
Editor's Rating: (4.8 / 5)
- Type: Full synthetic
- Viscosity: 0W-20
When you demand the best performance from your car's engine, you'll also need to make sure that it gets only the best, including engine oil, and that's exactly what this Valvoline oil offers.
It's a premium quality and full synthetic oil, designed for high-performance engines and to fulfill the standards of all leading engine makers.
This oil will work on a variety of cars, including those that run on gasoline and on diesel. It even works well on hybrids and is the perfect oil for in-warranty services, where API specifications are strictly observed, such as with Toyota and Honda vehicles.
In addition to being the best 0W-20 synthetic oil in this review, this oil also features sludge protection, high- and low-temperature protection, better fuel efficiency, and you can either get this 5-quart container or just a quart container, or a 3-pack of 5-quart containers.
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10. Lucas Oil 10299 Magnum CJ-4 Synthetic Motor Oil
Editor's Rating: (4.8 / 5)
- Type: Blended synthetic
- Viscosity: 15W-40
Lucas Oil's Magnum CJ-4 is a blended synthetic oil, including all of Lucas' premium oil additives to create the perfect heavy-duty oil for diesel engines.
It's 15W-40 viscosity shows just how heavier-duty it is. This improved viscosity helps in prolonging oil drain intervals up to 30,000 miles because the higher viscosity is better in trapping more contamination while maintaining its lubricity.
The formula also reduces engine wear, oil consumption, oxidation, and thermal breakdown. Plus, it comes with a high level of detergents to keep the engine clean and it helps in maintaining the life of catalytic converters.
Although you can practically use this oil in all kinds of engine, its main application is in heavy-duty diesel engines and this makes it impractical for use in normal diesel and gasoline engines.
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11. Mag 1 20139 Full Synthetic Oil
Editor's Rating: (4.8 / 5)
- Type: Full Synthetic
- Viscosity: 0W-20
This fully synthetic oil from Mag 1 features the purest additives and the most advanced formula to produce an oil that's perfect for all passenger car engines.
Its benefits include meeting or exceeding GM's Dexos1 oil specifications, long-term engine protection, better fuel economy, and mileage, as well as compatibility in both hot and cold weather.
With its light viscosity, you get a modern engine protection with friction management and wear protection, without adding any other resistance to the engine.
It's ideal for gasoline-fueled passenger cars, SUVs, and light trucks, including gasoline powered hybrids, however, it's not ideal for heavier-duty vehicles.
This offer is for a 5-quart container and you can also get it in a 3-pack of these 5-quart containers.
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12. Honda GL1800 HP4S Synthetic Oil Package
Editor's Rating: 
(4.3 / 5)
- Type: Full synthetic
- Viscosity: 10W-30
Honda is an unmistakable brand when it comes to engines, as well as cars, motorbikes, and lots of other vehicle types. So, when Honda comes out with its own oil blend, then you should pay attention.
This package includes 4 quarts in separate quart containers of Honda's HP4S oil, 1 Honda oil filter, and 1 drain plug washer. The parts are direct from Honda and are completely genuine, meaning you'll get only the best.
The best things usually come at a price and so too does this package have its price, but when you consider that it's direct from Honda, then the price starts to make sense.
Honda's HP4S oil does not contain MOLY but it's compatible with both synthetic blend oils like HP4 and regular mineral oils like GN4. It works great in motorcycles, scooters, ATVs and in, of course, cars.
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The Best Synthetic Oil Buying Guide
There are many factors that differentiate one synthetic oil from the other and you'll need to understand them so you can make the right choice when choosing an oil brand for your car.
These factors are as follows.
#1. Full Synthetic vs Synthetic Blend Oils
The first major difference between synthetic oils is the distinction between a fully synthetic and a synthetic blend oil. A fully synthetic oil is entirely made from synthetic materials while a synthetic blend oil is a mixture of a fully synthetic oil with standard motor oil.
Full synthetic oils are custom designed to offer specific characteristics that a car needs for the optimal functioning of its engine and for this reason, they were originally used mostly in high-performance cars. Their disadvantage is that they are costlier.
Synthetic blend oils, on the other hand, combine these good features of fully synthetic oils with the advantage of standard motor oils, which is a cheaper price.
#2. Compatibility
If you're upgrading from standard motor oil to synthetic oil and you're wondering if you can combine the two, the simple answer will be: Yes, you can but should you?
Nothing stops you from mixing both oils but remember that the major reason you're switching to synthetic oil is the many benefits it offers. So, mixing it with standard motor oil will naturally cut down on these benefits.
To get the best performance, you'll need to drain the oil before introducing the new one. Also, check to make sure that your vehicle is a modern engine (from 2,000 model) that will benefit from synthetic motor oil before going ahead.
#3. Viscosity Grade
Oil viscosity is a measure of how thick or thin it is, and since oil tends to thin out at higher temperatures, heavier-duty engines need thicker or more viscous oils to keep running smoothly and prevent tear and wear when doing serious work.
On the other hand, if the oil is too thick, then your engine could suffer from startup issues. So, you need to use an oil with the right viscosity for your car's engine and this rating is usually provided in the car's manual.
If you haul heavy loads or drive a lot in a hot environment, then you can choose an oil with a slightly higher viscosity and if you live in a cold region or just use the car for light errands, then an oil with a slightly lower viscosity rating would be great.
Oil grades are either given as 5W-30 or SAE 30, for example. When a 'W' is present, it states the oil's viscosity at a cold (Winter) temperature, which in this case would be 5. The 30 though, refers to the oil's viscosity at 100 Centigrades, which is generally considered a standard engine-operation temperature.
#5. Additives & Brands
Additives are what make a synthetic oil to stand out. There are so many different types of additives that you'll find in a synthetic oil and different manufacturers also have their own unique formulas for combining these additives.
This means that two oils may seem to have the same composition but end up working entirely differently. So, if you find a brand that works well for your car, then you might want to stick to it.
#6. The Additives
Following is a list of the major additives you'll find in synthetic oils. Do keep in mind that you'll hardly find them all together in one oil and that each manufacturer has its specific formula.
- Anti-foaming agents prevent the oil from foaming
- Anti-wear agents are different materials that lengthen an engine's lifespan
- Antioxidants help prolong the oil's life by slowing down its degradation
- Conditioners soften seals and help them to expand and contract better
- Detergents help to clean up an engine and prevent the buildup of gunk and debris
- Corrosion inhibitors protect your engine from corrosion
- Dispersants stop the clumping of particles and the buildup of sludge
When to Change Your Car's Engine Oil
The old advice goes you should change your car's engine oil every three months or 3,000 miles but that advice has gotten outdated because of the many advancements in the automobile industry.
You can find many cars that can drive for up to 5,000 and even 10,000 miles before needing an oil change. This is thanks to improved engine design and manufacturer's requirements of using better-quality oils in modern cars.
To know the best time to change your car's oil, you'll need to conduct the owner's manual and then consider your personal driving habits. If you drive more intensely or pull heavy loads, then changing your oil before the recommended time isn't bad at all.
Else, you can just wait for the oil replacement light on your dashboard to come on. This is mostly possible in modern cars, of course, but you can also depend on the old oil level check as well.
You should check your car's oil level at least once a month. When the oil loses its transparency and turns really black, then it's time to consider changing it. You can also touch it and rub the oil between two fingers. If the oil feels coarse or gritty, then it probably needs changing.
A final condition to changing your car's oil is when you hear increased engine noise or you've simply clocked over 10,000 miles since your last oil change.
Conclusion
We've reached the end of this best synthetic oil review and you've seen the wide offer of engine oils out there and their different specialties.
You can see that no single blend of synthetic oil is the best because some get designed for heavier-duty jobs while others come with performance in mind and others are for older engines.
In making your choice, therefore, you should focus on your engine and try to figure out which synthetic oil formula will best serve it.