Reviews

Best Synthetic Oils: Invest in Your Engine’s Long-Term Health

What’s in your engine? Find out which synthetic oil is best for your ride.

Entering our 7th season of /DRIVE on NBC Sports, and with millions of YouTube and Facebook followers, The Drive is a leading authority of all things automotive.

The Drive on NBC The Drive on YouTube The Drive on Facebook

The Drive and its partners may earn a commission if you purchase a product through one of our links. Read more.

BY Norah Tarichia / LAST UPDATED ON April 21, 2021

Gone are the days when drivers solely relied on conventional motor oils for their vehicles. Their unpredictability, impurities, and in some cases, toxicity necessitated the need for synthetic oils as a game-changer in the industry. Synthetic oils were introduced to drivers in 1997, and although more expensive than the alternative, synthetic oils quickly gained a large following due to their consistency and superior performance in comparison.

 

Generally, most synthetic oils are better than conventional oils, but some synthetic oils perform better than others. This is because synthetic oil manufacturers have different formulations tailored for different operating conditions and engine configurations. We will have an in-depth look at the types of synthetic oils available so you can choose the best option for your engine.

Best Overall
Mobil 1 Advanced  Full Synthetic Motor Oil
LEARN MORE
Summary
Summary

This motor oil is an SAE 5W-30 formulation designed to offer maximum protection to your engine for about 10,000 miles.

Pros
Pros
  • Promotes fast cold weather starts 
  • Improves fuel economy
  • Lubricates the engine to reduce wear and tear 
  • Resists deposits and sludge build-up
Cons
Cons
  • Not approved for some vehicle brands, such as Audi 
Best Overall
Mobil 1 Advanced  Full Synthetic Motor Oil
Best Value
Valvoline Advanced Full Synthetic SAE 5W-30 Motor Oil
LEARN MORE
Summary
Summary

Sporting a 5W-30 configuration, this motor oil offers about 40 percent more wear protection than most motor oils. It can be used on cars, SUVs, and trucks.

Pros
Pros
  • Great high- and low-temperature protection
  • Compatible with most conventional and synthetic oils 
  • Improves fuel efficiency 
  • Promotes faster oil flow for quicker cold starts
Cons
Cons
Bottle has a fragile cap that should be handled with care
Best Value
Valvoline Advanced Full Synthetic SAE 5W-30 Motor Oil
Honorable Mention
Pennzoil Ultra Platinum Full Synthetic 5W-30 Motor Oil
LEARN MORE
Summary
Summary

Recommended for gas engines, this 5W-30 synthetic oil offers optimal wear protection to your engine. It works on almost all types of vehicles, including ones with turbocharged engines. 

Pros
Pros
  • Promotes better fuel economy so you can drive an extra 550 miles per year
  • Keeps your pistons cleaner for longer
  • Lubricates and protects your engine 
  • Maintains efficiency and flow in both cold and extreme heat environments 
Cons
Cons
  • On the expensive side 
  • Doesn’t condition older seals 
  • May be harmful to the environment if disposed of incorrectly
Honorable Mention
Pennzoil Ultra Platinum Full Synthetic 5W-30 Motor Oil

Why Trust Us


All of our reviews are based on market research, expert input, or practical experience with most products we include. This way, we offer genuine, accurate guides to help you find the best picks.

Learn more

Best Synthetic Oils Reviews & Recommendations 2021

Best Overall
Mobil 1 Advanced  Full Synthetic Motor Oil

This SAE 5W-30 formulation is designed to protect your engine for up to 10,000 miles by lubricating the metal components to minimize wear. It also reduces impurities by resisting sludge and deposit build-up to restrict oil flow and gradually reduce horsepower. Since engines operate in both hot and cold temperature conditions, the motor oil maintains its thermal and oxidation stability up to 500 degrees Fahrenheit to prevent heat damage. It also maintains its viscosity even when temperatures dip to -30 degrees Fahrenheit for quicker cold weather starts. When this oil starts to turn slightly dark brown, that’s when you know it’s time for an oil change. 


While it may not be the best choice for old engines, this oil is an excellent choice for almost all types of modern vehicles, including high-performance, turbocharged, supercharged gas, and diesel engines.

Best Value
Valvoline Advanced Full Synthetic SAE 5W-30 Motor Oil

Valvoline is known to provide top-notch car care products. This particular synthetic oil is very efficient and comes at an attractive price. It's able to enhance the overall engine performance right after the application, making your vehicle smooth and quiet. The oil works to reduce wear and protect the engine parts from sludge and varnish. It also offers high-temperature protection in demanding driving conditions as well as cold-temperature protection for quick start-ups. You'll find it quite handy in maintaining fuel efficiency, too. The product is compatible with all conventional and leading synthetic motor oils, and you get to pick the bottle size that works the best for you. 


What could bother you the most with this product is the cap design. It's fragile and might break easily, so you need to handle it carefully. Some buyers even complained about the bottle leaking straight from the package. However, the manufacturer is quick to resolve the issue. 
Honorable Mention
Pennzoil Ultra Platinum Full Synthetic 5W-30 Motor Oil

Pennzoil synthetic oil is one of the best products within the category. With the help of the revolutionary PurePlus Technology, the oil is converted from pure natural gas. Therefore, it's a high-quality oil that contains fewer impurities than products made from crude oils. Overall, the oil is made for extreme performance and demanding road situations. It cleans and protects the engine, reducing wear, and increasing gas mileage. With this oil, you'll have cleaner pistons, better fuel economy, and overall better engine performance. Your vehicle will drive smoothly and quietly at all times, regardless of the weather and road conditions. Also, you get to use this synthetic oil on all kinds of cars, SUVs, vans, trucks, and other vehicles.


The main drawback of this product is the price. Although you can get an excellent deal for a pack of three and six bottles, Pennzoil is still not the best option for those who are on a limited budget.

Honorable Mention
Castrol EDGE 0W-40 Synthetic Motor Oil

Here’s another quality full synthetic oil that proves to be ideal for those on a limited budget. It's a reliable 0W-40 synthetic oil compatible with all kinds of vehicles, including models from Mercedes, Porsche, Ford, and more. You get to use it for enhancing your vehicle's engine performance and making it smoother and quieter. This synthetic oil offers superior engine protection. It works against deposits, wear, and oxidation. Overall, the product reduces engine wear in general, prolonging its lifespan, and making it significantly smoother. It's much more efficient than regular conventional and synthetic blend oils, so you'll see the improvements in your vehicle performance right away. 


When it comes to the product itself, you might have an issue with the design of the container. There's a see-through strip on the side that should allow you to estimate how much oil you poured out, but it's difficult to read. Because of that, you might end up adding more oil than needed. 

Honorable Mention
Castrol GTX MAGNATEC 5W-30 Full Synthetic Motor Oil

Castrol synthetic oil is one of the best budget-friendly options you can find on the market. It's designed to reduce engine wear and ensure smooth and quiet rides. The results are even better with long-term use. The oil is very efficient on loud engines, and it significantly improves high mileage on different vehicle models. It even adds a layer of protection that stays on from the moment you start the vehicle. This way, you'll drastically reduce the engine wear and keep it in perfect condition. Additionally, the product comes in a conveniently designed bottle. You even get to pick the size and the number of bottles as well as the configuration. 


However, keep in mind that this is an inexpensive option. Therefore, you might need to change the oil sooner than with the other high-end products. Also, several buyers complained about the package coming in poor shape. It seems that some leaks might occur during shipping.

Honorable Mention
 Liqui Moly Premium 5W-40 Synthetic Motor Oil

Liqui Moly is a popular and highly-rated company that offers a wide range of car care products. This time, we have its synthetic oil that proves to be of excellent quality. It's versatile and formulated to ensure outstanding engine performance. The oil is suitable for both gas and diesel engines. It cleans, maintains, and protects the engine, making it smooth and quiet. The product also works to provide quick starts at low temperatures, and it protects the vehicle from high temperatures. It's highly efficient and beneficial for long-term use. 


However, this is a pricey product. If you're looking for a budget-friendly option, you might want to check out some of the other synthetic oils on our list. Also, the cap is awkwardly designed and might be a little tricky to open. If you’re to avoid leaks, you’ll need to carefully pour the liquid.

Best High-Mileage Synthetic Oils Reviews & Recommendations 2021

Best Overall
Castrol EDGE High-Mileage Motor Oil
LEARN MORE
Summary
Summary

This is an SAE 5W-30 synthetic oil designed to improve efficiency and prevent emission system failure in vehicles with over 75,000 miles.

Pros
Pros
  • Keeps the engine running clean by reducing sludge and harmful deposits 
  • Can help improve fuel economy 
  • Helps reduce leaks in older vehicles
Cons
Cons
  • Might sometimes burn 
  • You need to use a heavy oil filter
Best Overall
Castrol EDGE High-Mileage Motor Oil
Best Value
Valvoline High-Mileage with MaxLife
LEARN MORE
Summary
Summary

This high-mileage oil helps to keep older engines that suffer from wear and tear cleaner and running for longer.

Pros
Pros
  • Reduces sludge and deposit buildup
  • Reconditions hardened or shrinking seals 
  • Lubricates moving parts to prevent damage
Cons
Cons
  • Oil burn-off resistance decreases after 1,000 or 2,000 miles with the oil
  • Shorter change intervals
Best Value
Valvoline High-Mileage with MaxLife
Honorable Mention
Royal Purple 11748 HMX High Mileage Synthetic Oil
LEARN MORE
Summary
Summary

This motor oil is designed to restore engine performance in high-mileage vehicles. It contains zinc and phosphorus additives for anti-wear protection.

Pros
Pros
  • Prevents wear and corrosion
  • Reduces friction for smoother engine performance 
  • Reduces sludge and harmful engine deposits
Cons
Cons
  • A more expensive motor oil 
Honorable Mention
Royal Purple 11748 HMX High Mileage Synthetic Oil
Best Overall
Castrol EDGE 03128C High-Mileage Motor Oil

This motor oil sports an SAE 5W-30 configuration, which is an indication that it performs well in extreme temperature conditions. To further boost its strength, it’s formulated with fluid titanium technology so it can resist breakdown when exposed to harsh operating conditions. It’s formulated for vehicles with over 75,000 miles on the odometer. It can help improve the engine’s performance by reducing sludge, deposits, and other impurities so your engine can run cleaner and smoother with frequent use. It also reduces phosphorus in your emission system to prevent early failure. 


While it does a fine job at reducing impurities, the oil may still have tiny particles that can still produce high emissions. You may have to upgrade to a high-quality filter with better capturing efficiency.

Best Value
Valvoline High-Mileage with MaXLife

As a high-performance, high-mileage oil, Valvoline MaxLife oil sits on the premium side of life-extending oil options available on the market today. Meant for cars with over 75,000 miles on the engine, the oil is formulated to protect or repair common old engine issues such as seal leaks, oil burnoff, deposit and sludge buildup, and more. As a synthetic blend, the oil offers a lot of longevity with less wear than other competitors above the 5,000-mile mark after an oil change. This is one of a few high-mileage oils that perform well if you change it every 10,000 miles instead of the usual 5,000. While it's not necessary to extend the oil change frequencies, the longevity of the oil does make it more convenient if you want to keep oil changes down as much as possible. 


You can expect noticeable performance gains to remain for several thousands of miles, but the oil burn-off resistance may reduce after the first 1,000 or 2,000 miles following the latest oil change.

Honorable Mention
Royal Purple 11748 HMX High Mileage Synthetic Oil

If you have a high-mileage vehicle, you can give it maximum wear protection with Royal Purple's SAE 5W-30 High Mileage Synthetic Oil. It's fortified with zinc and phosphorus anti-wear additives, coupled with Royal Purple's proprietary Synerlec additive technology for superior wear protection—the latter also improves the oil's film strength so it can resist degradation. On top of that, it contains detergents that reduce harmful carbon deposits in the oil and consequently promote longer engine life. Overall, it's an excellent lubricant that rejuvenates hardened seals to reduce oil consumption and is recommended for four-cycle gas engines with a mileage of 75,000 miles or more. 


It's recommended that you should first perform a quick cleanup by draining it twice after every 3,000 miles, then you can extend the drain interval to 15,000 miles.

Honorable Mention
Mobil 1 High Mileage Motor Oil

For engines with over 70,000 miles that struggle with cold starts, the Mobil 1 High Mileage Oil is a solid choice for eliminating the problem. Designed to work within a temperature range of -30 to 500 degrees Fahrenheit, this 5W-20 motor oil promotes hassle-free engine performance even when the engine is subjected to severe temperature change. It outperforms most conventional oils when it comes to reducing friction and conditioning hardened or shrinking seals to help prevent leaks. It also includes detergents that go further to reduce deposits and sludge buildup to help lower emissions. 


Sure, it can last the recommended 10,000 miles before having to be drained, but Mobil 1 recommends draining it in intervals of 3,000 to 5,000 miles for the first two uses.

Honorable Mention
Castrol's GTX High-Mileage Oil

Castrol's GTX High-Mileage Oil is a standout option for older vehicles that need some extra help running when engine parts are starting to wear down. The blended oil has a good amount of durability and protection to resist burn-off and viscosity breakdown. More importantly for a high-mileage oil, it also helps to fight against sludge build-up and prevent failure of parts like the emission system and the catalytic converter. This oil has a very good track record with engines that have mileage counts of around 150,000 miles. It works well with general engine maintenance and can be replaced every 5,000 miles without the worry of wearing out too early. 

Best High-Performance Synthetic Oils Reviews & Recommendations 2021

Best Overall
Valvoline VR1 Racing Oil
LEARN MORE
Summary
Summary

This oil is formulated for use in track cars and other vehicles with high-performance engines. It’s formulated with well-balanced additives that help with anti-wear protection.

Pros
Pros
  • Includes a boosted level of zinc and phosphorus additives than other synthetic oils
  • Reduces friction and increases engine horsepower
  • Good burn resistance
Cons
Cons
  • Not as good for high mileage vehicles as other dedicated options
Best Overall
Valvoline VR1 Racing Oil
Best Value
Castrol EDGE Extended Performance
LEARN MORE
Summary
Summary

This motor oil is formulated for high-stress applications such as towing or hauling vehicles or high-performance vehicles.

Pros
Pros
  • Long drain interval of about 20,000 miles
  • Resists degradation or oil breakdown even when  under pressure
  • Reduces friction on moving metal parts 
Cons
Cons
  • Comes with a tough protection seal that can be difficult to open
Best Value
Castrol EDGE Extended Performance
Honorable Mention
Penn Grade Partial Synthetic Racing Oil
LEARN MORE
Summary
Summary

This is a semi-synthetic racing oil that‘s designed to withstand high temperature and extreme pressure conditions. It’s an SAE 10W-30 formulation.

Pros
Pros
  • A good degree of resistance against viscosity and thermal breakdowns
  • Contains strong detergents that clean the engine and make it run quieter 
  • Can lead to a smoother and more responsive engine
Cons
Cons
  • More expensive than other general oils
  • Bottle doesn’t come with a convenient handle
Honorable Mention
Penn Grade Partial Synthetic Racing Oil
Best Overall
Valvoline VR1 Racing Oil

Valvoline's VR1 Racing Oil has almost everything true weekend racers need out of a high-performance oil while retaining a high degree of compatibility with everyday engines. While some racing oils are meant just for the rough conditions of a race, this one offers a good balance between the durability necessary to survive and the formula necessary to help most engines stay running for longer. The formulation comes with a high content of zinc and phosphorus to extend the normal anti-wear properties of other high-performance oils. As a racing oil, it is compatible with gasoline blends that use partial or full amounts of alcohol as well. The burn resistance is good, and the formula works equally well for high-mileage vehicles as it does in racing conditions.


However, a true high-mileage formula is recommended if you want the best results in terms of longevity for older vehicles.

Best Value
Castrol EDGE Extended Performance

This isn't necessarily a true racing oil like other offers, but Castrol's EDGE Extended oil has enough long-term performance results to make it worth a go if you are a weekend racer. In other words, the oil does a good job of performing well in general racing conditions and can be used for other transportation needs like everyday driving and towing/hauling. This makes it a good option for anyone who uses their high-performance car as a daily commuter as well. The oil comes in a 5-quart bottle and is available in large case packs for better value and bulk. The "extended performance" part of the oil comes from the formula's longevity that's designed to last up to 20,000 miles before needing a change. While the lengthy oil change span may be too idealistic for some older vehicles, it is easy to expect the oil to last 10,000 to 15,000 miles without showing major signs of degradation, breakdown, or burn-off.

Honorable Mention
 Penn Grade Partial Synthetic Racing Oil

Penn Grade's partial synthetic racing oil is a good all-around option for weekend racers or vehicle owners who use their rides for towing and hauling. The oil performs well in conditions where the engine and individual components are under high loads of torque and pressure to perform. There is also a small noticeable boost in engine efficiency and horsepower output but not as much as true racing or high-performance oils designed to get the most out of the engine in terms of power. The oil has a high degree of resistance and protection against most oil issues like thermal and viscosity breakdowns. Its longevity is equally useful in high-performance driving conditions as it is with older, high-mileage vehicles that need extra protection from common wear and tear. 


Given the price of the oil, however, it doesn't offer the most in terms of value compared to true budget options that exist in the high-performance oil niche.

Honorable Mention
Royal Purple High-Performance 5W-30

Royal Purple is a renowned full synthetic oil brand among auto enthusiasts and racers everywhere, and this oil delivers optimal performance. The secret behind Royal Purple’s superior performance is its Synerlec additive. This additive works on a molecular level by generating extra-strength ionic bonds with the metal surfaces in your car’s engine. The oil responds with increased viscosity, strength, and lubricity, so your engine performs at its prime—even under extreme stress. This makes it a wonderful choice if you have a lead foot, race your ride, or simply want maximum engine performance. You can expect an increase in fuel efficiency and oil change intervals. Initially, you’ll have to change the oil at 3,000 miles when switching over to Royal Purple, but you can enjoy 7,500 to 10,000 miles between oil changes afterward.


This high-performance motor oil has a few shortcomings. If you’re on a tight budget, its higher-end price may push you over the edge. Also, there have been some cases where the containers leak if stored for extended periods. With that said, if your blood type is 5W-30, and your engine sees its redline multiple times per day, this is perhaps the best synthetic motor oil you can get for your needs.

Honorable Mention
Mobil 1 Extended Performance 5W-30

The Mobil 1 Extended Performance offers unparalleled protection against engine wear and guarantees efficiency and longevity for automotive engines. That’s probably why most performance and luxury car manufacturers choose to run Mobil 1 in their cars right out of the factory. Mobil 1 boasts incredible anti-wear properties in both extremely low and high temperatures, thanks to its SuperSyn technology. This makes it a fantastic option for drivers in all types of climates. We were also impressed with the potent blend of cleaning and performance-enhancing additives found in this synthetic oil. You can expect a major boost in engine smoothness, responsiveness, and fuel efficiency when you run Mobil 1 in your ride. Throw in the fact that users can expect to get up to 15,000 miles between oil changes, and you can easily see why we chose this for the best synthetic motor oil brand. 


There are a few minor drawbacks, chiefly the high price tag this synthetic engine oil commands. 

Best Synthetic Oils for Diesel Engines Reviews & Recommendations 2021

Best Overall
Motul 5W-40 Synthetic Gasoline and Diesel Engine Oil
LEARN MORE
Summary
Summary

This is an SAE 5W-40 synthetic oil that can be used in both gas and diesel engines. It helps to reduce engine wear and promote better performance.

Pros
Pros
  • Improves gas mileage 
  • Meets the demands of severe driving conditions
  • Makes the engine run smoother and quieter
Cons
Cons
  • A bit pricey 
  • Top nozzle is somewhat flimsy
Best Overall
Motul 5W-40 Synthetic Gasoline and Diesel Engine Oil
Best Value
Valvoline European Vehicle Full Synthetic Motor Oil
LEARN MORE
Summary
Summary

Sporting an SAE 5W-40 configuration, this synthetic oil is designed to meet the demands of most European gas and diesel engine vehicles.

Pros
Pros
  • Optimal protection from sludge and varnish deposits
  • Great cold and hot weather protection 
  • Can be used on turbocharged vehicles
Cons
Cons
  • Quality of the case is lackluster
  • Cases can come from the factory with a broken seal
Best Value
Valvoline European Vehicle Full Synthetic Motor Oil
Honorable Mention
Mobil 1 Turbo Diesel Synthetic Motor Oil
LEARN MORE
Summary
Summary

This synthetic oil formula is a solid option for turbocharged diesel trucks.

Pros
Pros
  • Excellent hot and cold weather performance 
  • Can help improve horsepower and gas mileage 
  • Resists formation of sludge and varnish
Cons
Cons
  • Won't prevent leaks in older engines
Honorable Mention
Mobil 1 Turbo Diesel Synthetic Motor Oil
Best Overall
Motul 5W-40 Synthetic Gasoline and Diesel Engine Oil

The Motul synthetic oil is a trusted product compatible with gasoline and diesel engines. The oil is specifically designed for high-performance cars and demanding road conditions. It features a powerful formula that treats the engine and makes it clean, smooth, and super quiet. The oil lubricates and cools down the engine, keeping it at peak power during every ride. It also increases gas mileage and reduces engine wear at extreme temperatures. You'll notice the improvement right after the application, although the real results will show in long-term use. All in all, this synthetic oil will significantly improve your vehicle's performance and ensure more enjoyable rides. 


What could be an issue with this product is the price. The oil is on the expensive side, especially considering it comes in a 1.32-gallon bottle. The top nozzle also might break and cause leaks, so make sure to store the product upright.

Best Value
Valvoline European Vehicle Full Synthetic Motor Oil

If you need a lot of diesel-use oil, Valvoline European Vehicle Full Synthetic Motor Oil is hard to beat in terms of sheer quantity and value. Coming in 1-quart and 6-case packages, the oil shines a lot when it comes to buying in bulk. Each container offers plenty of oil for a single change on larger engines or multiple changes on smaller engines. Combined with decent protection and performance-boosting properties, this one is hard to beat as a general diesel all-arounder. The oil is designed for the extremes, which in the mind of Valvoline, means hot and cold conditions. The oil offers good results in freezing temperatures and with cold-weather starts. For hotter temperatures, it resists degradation so the friction reduction coating doesn't break down over time. 


The size of the container and multi-container package options make it a perfect fit for large vehicle owners. The quality of the case, however, is a bit hit or miss. 

Honorable Mention
Mobil 1 Turbo Diesel Synthetic Motor Oil

This synthetic oil is a 5W-40 formulation that provides excellent high and low-temperature protection. It’s designed to work within a temperature range of -53 to 400 degrees Fahrenheit and maintains its viscosity even under intense stress. This helps to keep the engine well lubricated to prevent premature wear. Moreover, it resists the formation of varnish at high temperatures and sludge at low temperatures, thereby helping to keep your engine running clean all year round. Since your engine will run with fewer power-robbing deposits, its horsepower may improve, and you will also experience better fuel economy. 

Honorable Mention
Shell Rotella T6 Motor Oil

Shell's Rotella T6 Diesel Engine oil is somewhat unique in that it offers the performance results of higher-priced options with the money-saving value of budget options. The formula of the oil is engineered to work with both gasoline and diesel engines, with a special focus on high-torque, high-stress conditions many heavy-duty vehicles like full-size trucks may encounter on the road. At the same time, its plethora of sizes and bulk options means you can buy more for less to get some extra savings. High-performance gains tend to last beyond the 5,000-mile mark, and the formula works well in engines that have more variation in certain properties like temperature. The oil also works well in different types of engines, including some motorcycle engines. It can also be used on high-mileage engines to reduce the noticeable "clinks" and "bangs" that tend to arise with age. 


For the most part, the only downside to this oil is a slower-than-average rap-up and performance results that aren't quite suitable for racing conditions since the oil can break down more quickly in extreme racing conditions.

Best Synthetic Oils for Motorcycles Reviews & Recommendations 2021

Best Overall
 Castrol Power Synthetic Oil
LEARN MORE
Summary
Summary

A good synthetic oil designed for larger, more powerful bike engines used in high-performance riding.

Pros
Pros
  • Engine noise reduction is noticeable
  • Small gains in horsepower and fuel efficiency
  • Ideal for wet clutch motorcycles
Cons
Cons
  • Frequent oil changes are necessary to maintain performance gains
  • Shorter shelf life than other motor oils
Best Overall
 Castrol Power Synthetic Oil
Best Value
Ravenol Four-Stroke Oil
LEARN MORE
Summary
Summary

One of the best synthetic oils to choose for four-stroke engines. Noticeable gains with on- and off-road use.

Pros
Pros
  • Good improvement with shifting quality
  • Cooler running temperatures
Cons
Cons
  • Variable results depend on the engine type
  • Longevity of the oil is shorter than other options
Best Value
Ravenol Four-Stroke Oil
Honorable Mention
Motul 104092 Synthetic Engine Oil
LEARN MORE
Summary
Summary

A safe synthetic oil for 4-stroke motorcycles with catalytic converters. It’s formulated with ester technology for better engine response.

Pros
Pros
  • Noticeable gains on first use
  • Withstands extreme pressure conditions 
  • Great on- and off-road performance
Cons
Cons
  • Leans on the expensive side
  • Gains are somewhat unnoticeable in cold weather
Honorable Mention
Motul 104092 Synthetic Engine Oil
Best Overall
Castrol Power Synthetic Oil

Castrol's Synthetic Motorcycle Oil is designed for larger, more powerful bike engines that get used near the limits of their capabilities (i.e. the points where the parts experience the most wear and tear). Suitable for four-stroke motorcycle engines, the oil's formula has a good balance of part protection and performance gains, so you can buy this oil with the expectation of getting some noticeable signs of performance enhancements. Slight signs of improvement include smoother shifts and cooler running temperatures, especially when the engine is running at high speeds or for long periods. The exact level of improvement will depend on the engine itself and how you use it, but most happy customers report seeing noticeable effects almost immediately after application. 


The longevity of the oil, however, lacks compared to other motorcycle oil options. Smooth-shifting tends to go first, so frequent and routine oil changes will be necessary to maintain the performance gains.

Best Value
Ravenol Four-Stroke Oil

Designed for general four-stroke engine use, Ravenol's Motorbike oil is marketed as having the "latest lubrication from Germany." While that doesn't mean much, the oil has some noticeable gains it offers when applied to an on- or off-road engine that needs extra lubrication to perform well under extreme conditions. This means it's a good solution for high-speed bikes or off-road engines that take a lot of abuse out in the wild. The general efficiency the oil delivers tends to be noticeable right from the start after a change. Engine noises go quiet, shifting performance gets smoother, and some users even report slight gains in horsepower and fuel efficiency. 


While this oil won't work magic on a neglected or old engine, it offers just enough to take a normal four-stroke engine over the edge in terms of performance and efficiency. With that said, results are akin to other competitors, so the real draw of the oil is with its relatively low price tag.

Honorable Mention
Motul Synthetic Engine Oil

This safe formula is low in sulfur and phosphorus because, while they are excellent anti-wear compounds, they can gum up and damage catalytic converters. Plus, it’s formulated with ester technology, which provides constant lubricity even under extreme conditions to provide a better and smoother engine response. Also, the ester material coupled with anti-wear additives helps maintain this oil’s shear stability even when under intense mechanical stress to protect the gearbox better. Besides motorcycles, you can also use this oil on ATVs and UTVs. 


Most users have noticed an almost immediate improvement in their motorcycle’s performance, so we aren’t surprised that it comes with a higher price tag than most motorcycle oils on the market. Another thing we also noted is that it works best in summer than in winter.

Honorable Mention
Valvoline 4-Stroke Motorcycle Full Synthetic Oil

For the best riding experience and improved performance, one of the best motor oils to go for is Valvoline's full synthetic oil for four-stroke engines. It's a thermally stable formula with anti-friction additives that resist oil breakdown and improve engine performance even under high temperature or high RPM conditions. It also maintains maximum lubricity under the conditions mentioned above for better protection of wet clutch applications. Consistent use and following through with the recommended oil drain intervals can lead to smoother shifting, better combustion, and eventually, your bike will achieve peak performance. Additionally, it contains cleaning agents and particle dispersants that help minimize wear and keep your engine clean. 


The main downside of this product is that the bottle isn't convenient to hold since it doesn't have a handle, but that shouldn't be an issue for most people.

Benefits of Synthetic Oil

  • Extend engine life. The best synthetic motor oil is formulated to have a high degree of natural solvency, meaning it can clean and remove deposits. This keeps your motor sludge- and deposit-free so it can run as smoothly and efficiently as possible, as well as extend the lifespan of engine seals and other components.
  • Maximize engine performance. There’s a reason why high-performance vehicles and race cars all run synthetic oil from the factory—superior engine performance. Enthusiasts often report that they perceive more power and torque from their engines when they use synthetic oil. At the very least, synthetic oil is slicker than conventional oil, so it’ll make your ride run smooth as silk. 
  • Improve fuel mileage. Premium synthetic oil reduces the amount of friction that occurs between key engine components, therefore making your engine run smoothly and efficiently. Theoretically, this increases the fuel mileage of your vehicle, so you’ll spend more time on the road and less time (and money) at the pump.
  • Flows better in cold or hot weather. The proprietary formula of synthetic motor oil makes it flow better in extreme temperatures. During wintertime, its resistance to viscosity breakdown lets it flow freely regardless of how cold it is outside, so your car is less likely to break down due to cold starts. Alternatively, synthetic oil works at peak performance during hotter weather too.
  • Longer lifespan than conventional oil. The best full synthetic motor oil has a considerably longer lifespan than synthetic blends or conventional oil. In some cases, full synthetic oil has a change interval of up to 15,000 miles, compared to 3,000 miles for conventional motor oil.  
  • Saves you money in the long run. Although going synthetic initially costs more per quart than conventional, it saves you money in the long run. Not only will you get more mileage out of engine components and save money on fuel, but you’ll also enjoy savings on less frequent oil changes. That’s something every motorist can get revved up about.

Types of Synthetic Oil

Full Synthetic

Full synthetic motor oil is created in a laboratory with a unique molecular structure and is infused with additives to deliver optimal wear protection and performance for your engine. Unlike conventional oil, it is not derived from whole crude oil, so it’s formulated without any of the impurities that you’d find in conventional oil. The best synthetic engine oil brands use a proprietary blend of anti-wear and cleaning additives to make your motor run at its best.

Synthetic Blend

As the name implies, a synthetic blend motor oil is a mix of conventional oil and a brand’s synthetic base oil. Think of synthetic blend oil as a conventional oil fortified with synthetic supplements for better engine protection and performance. However, it’s worth mentioning that synthetic blends do not deliver the same caliber of performance and protection that a best-rated synthetic oil does. Still, if you choose not to spend a little more for full synthetic oil during your next oil change, you can rest assured knowing that a synthetic blend provides more benefits than conventional oil. 

Top Brands

Liqui Moly

Founded in 1957, Liqui Moly is a German company that manufactures oils, lubricants, and additives. The brand prides itself on offering premium quality products at a more accessible price point than its competitors. One of its top products is the Longtime High Tech 5W30 Synthetic Oil.

Mobil 1

Introduced in 1974, Mobil 1 offers synthetic motor oil and lubricant products. Its synthetic motor oil is perhaps the most recognized brand in the business, with prestigious auto manufacturers such as Porsche and Mercedes-Benz using Mobil 1 synthetic oil in all their vehicles. One of its best-selling products is the Extended Performance 5W-30.

Royal Purple

Established in 1986, Royal Purple is an American manufacturer of lubricant products for automotive, industrial, marine, motorcycle, and racing usage. It is best known for its motor oil products and garners the endorsement of car enthusiasts for its high-performance formula. A particularly popular product is the High-Performance 5W-30.

Valvoline 

Since its inception in 1866, Valvoline has gained a solid reputation in the car care industry as one of the best manufacturers of motor oils, additives, cleaners, and lubricants. This Kentucky-based company dedicates most of its efforts to making innovative products to improve the on- and off-road performance of motorcycles and vehicles. One of its popular motor oils is the Advanced Full Synthetic SAE 5W-30 Motor Oil

  Synthetic Oil Pricing

  • Under $30: You’ll find a few options for under $30 for a 5-quart container, though most of these products are synthetic blends. Not all value-priced synthetic and synthetic blend motor oil brands are created equally, so make sure you scour our synthetic motor oil reviews to see which one fits your needs.
  • $30-$39: The majority of synthetic motor oil products fall within this price range. You’ll find everything here, from high-performance motor oil to high-mileage oil. These options typically deliver a great mix of performance, efficiency, and value.
  • $40 and up: Some of the best engine oil in the world resides at this lofty price point. These premium synthetic oil products promise the best engine protection, performance, and efficiency.

Key Features

Viscosity

Viscosity grade is the most important factor in selecting the right synthetic motor oil for your needs. If you operate your car in a hotter climate or ring your engine out often, a viscosity of 10W-40 is best. For commuting in most warm or cold climates, a 5W-30 synthetic oil fits the bill. Finally, if you drive in conditions that could be described as arctic, a 5W-20 or even 0W-20 synthetic oil is advisable. 

Application

The labels on all types of synthetic oil list the specific application that the oil is designed for. Some common synthetic oil applications include higher mileage, extended performance, diesel engines, and motorcycles. Do your homework on your vehicle’s condition before you purchase the best synthetic oil for your needs.

Compatibility with Existing Oil

Before you add full synthetic engine oil to your ride, it’s important to note if the brand is compatible with other types of oil. If it isn’t, you’ll have to drain the existing oil before filling it up with the synthetic stuff. It’s also crucial to consult your owner’s manual to verify which type of oil your vehicle requires. For instance, most vintage vehicles were engineered to run best on conventional oil. 

Additives

Each synthetic motor oil brand adds its proprietary blend of additives to enhance certain properties. For instance, viscosity-index improvers work extremely well in ensuring that oil doesn’t get too thin at higher temperatures. Other additives like detergents are efficient cleaning agents designed to remove deposits and sludge from your engine. Determine which additives would provide the benefits you need the most before purchasing a synthetic engine oil.

Other Considerations

  • Price. If you’re on the fence about plunking down the price premium that certain high-end full synthetic oil brands command, it’s completely understandable. Expensive synthetic oil brands aren’t always objectively superior to less expensive brands. Conduct your synthetic oil comparison and research reviews online to determine which synthetic oil is right for you. 

Tips

  • If you are upgrading to synthetic oil, also consider upgrading to a high-quality oil filter so you can better protect your engine from small metal flakes and other microscopic by-products of combustion that can accelerate engine wear.  
  • It’s important to carefully read the label of synthetic motor oil containers. These labels list essential information about the synthetic oil viscosity rating, application, and, sometimes, the additives it contains.
  • Look for an American Petroleum Institute (API) rating donut somewhere on the synthetic oil container label. This seal of approval means that the synthetic engine oil has passed the API’s rigorous quality standards. To learn more about the API oil categories, click here
  • Before switching over to full synthetic oil, consult your vehicle’s owner manual to see if there are any break-in instructions to prep for the switchover. Also, make sure that the synthetic oil you intend on using is compatible with other types of oil. If it’s not, you’ll have to completely drain your existing oil before going full synthetic.
  • If you’re not afraid to get your hands dirty and change your car’s oil yourself, ensure that you don’t overfill your engine’s crankcase with oil. Overfilled oil can rinse into the crankcase and cause air bubbles to churn into the oil. This can stress the engine components, cause overheating, and even foul the spark plugs.
  • Check your oil at every other gas-up. For best results, run your car for 15 minutes then park it in a level place. Let it cool down for 15 minutes, remove the dipstick and wipe it with a clean rag. Reinsert the dipstick all the way, then pull it out to ensure the oil level is between the marks.
  • If you plan on doing a lot of towing or racing with your vehicle, consider adding an oil cooler if your ride isn’t already equipped with one. Oil coolers function the same way your radiator does and can dramatically increase the lifespan of your engine. 

FAQs

Q: What does API SM/CF and SL, SJ, SH, SG mean on my oil container?

API sets industry-recognized standards for oil and petroleum products for passenger and commercial vehicles. The letters after API, like SM or SL, denote the quality of motor oil. Currently, the highest standard for passenger vehicles is SN. CF denotes a diesel engine or commercial vehicle standard, and the highest standard is CJ-4.

Q: Will I damage my engine if I switch from synthetic to conventional oil?

No, although you may experience a perceivable loss in protection, performance, fuel mileage, and longevity if you switch back to conventional oil. Be aware that some synthetic oil types aren’t engineered to be mixed with other oil types, so in this circumstance, you’ll have to drain your existing synthetic oil before adding any conventional oil. 

Q: Do unopened bottles of synthetic oil have an expiration date?

This largely depends on the individual manufacturer of synthetic engine oil. Some brands claim that unopened containers of their synthetic motor oil have a virtually unlimited shelf life if stored under ideal conditions. Alternatively, other brands like Mobil 1 claim that unopened containers of their oil last up to five years. Read the label of your synthetic oil container for this information and always follow the manufacturer’s expiration date.

Q: Will synthetic oil cause my engine to consume more oil?

This is another commonly-cited myth about synthetic motor oil, and it’s also false. Synthetic engine oil in no way causes your engine to consume more oil compared to conventional oil. 

Q: Is it true that some synthetic oil brands can last up to 15,000 miles?

Thanks to the innovative additives and other properties of modern synthetic motor oil, you really can follow the manufacturer’s recommended oil change interval without inflicting any harm on your engine. Note that the exact oil change interval may vary depending on your particular vehicle, so always consult your owner’s manual to make sure it doesn’t have a different recommended oil change interval. 

Final Thoughts

From our review, we concluded that the Mobil 1 Advanced  Full Synthetic Motor Oil is the best synthetic oil for engines that demand maximum protection. It retains its protective characteristics through thousands of miles of hard driving. If you are looking for a more budget-friendly option to keep your engine in top shape, then consider the Valvoline Advanced Full Synthetic SAE 5W-30 Motor Oil.