SAE 30 vs. 10w30: A Comprehensive Motor Oil Analysis

Engine oils come in various grades, which indicate their suitability for different driving conditions. The SAE 30 vs. 10w30 size-up highlights two lubricants of different grades, whose performance varies depending on the environment.

A noticeable contrast point is that SAE 30 is a single-grade lube, while 10w30 is a multigrade oil. The grading reflects their viscosity at varying temperatures.

There is plenty to learn about SAE 30 and 10w30, which we are glad to lead you through, touching on their similarities, differences, and functionality.

sae 30 vs 10w30 viscosity

What Is SAE Oil, And How Do They Grade Motor Oils?

You may come across lubricants with the SAE tag, begging the question, what does SAE mean on motor oil? SAE stands for the Society of American Engineers, presently known as SAE International, a body that determines and grades motor oils according to their viscosity.

SAE motor oil grading focuses on density at different temperatures and is denoted by numbers. Winter oils will have a number, starting from 0 to 25, in multiples of 5, followed by a ‘W’ indicating winter. Such oils have an excellent flow rate, even when temperatures drop. 10W engine lube is an example of winter oil.

On the other hand, regular motor oils have a number indicating their viscosity at standard operating temperatures. The numbers run from 20 to 60, in multiples of 10, though 8 and 12 are new entrants. Unlike winter lubricants, these don’t have a letter before or after the number.

Lastly, SAE also grades multipurpose oils, which are suitable for both regular and freezing conditions. Their grading has the first number followed by W, denoting that the oil is fit for winter, then another number after the letter, showing the lube’s grade in regular operating temperatures. 10w30 is an excellent example of a multigrade lubricant.

SAE 30 Oil Explained

SAE 30 oil is a monograde lubricant that typically lacks detergent, though some motor oil brands formulate the cleaners into this oil to boost its performance. SAE 30 is highly viscous, with a kinematic viscosity of 9.3-12.5 cSt at 100⁰ Celsius or 212⁰ Fahrenheit. Its density is around 0.875g/cm3 at 30⁰ Celsius (86⁰ Fahrenheit), while its viscosity index is 97.

SAE 30’s thickness makes it ideal for warm operating conditions, as it offers adequate film strength, which is crucial for part protection. This oil’s density is perfect for smaller and older engines, mostly found on agricultural equipment like lawnmowers and older vehicles and motorcycles.

This lubricant is unsuitable for cold starts, as it becomes thicker with temperature drops. Starting a car in the cold with SAE 30 will be challenging due to its poor flow rate, brought by its thickening. SAE 30 oil can be synthetic or mineral.

SAE 30 vs. 5w30: are they the same? These two engine lubes are not the same, considering that SAE 30 is a monograde oil suitable for regular and high operating temperatures. 5w30 is a multigrade oil that works fine for cold starts and standard running temperatures.

Nevertheless, they have similar operating temperature viscosity ratings. It means you can use SAE 30 and 5w30 interchangeably when hot.

What Is API, and How Do They Grade Motor Oils?

The American Petroleum Institute (API) is a trade association that evaluates and rates lubricants. API motor oil grading is congruent with standards set by the International Lubricant Specification Committee (ILSAC). The API engine oil classification hints at the lube’s compatibility with your engine.

How does API rate motor oils? We take you on a walk down history lane to answer this question. The year is 1920, and API is roughly a year old when it developed a classification system for car lubricants.

The system grades petrol and diesel engine oils differently. The rating for petrol engine lubes starts with the letter S, followed by another letter that indicates the engine’s year of manufacture. For instance, SA-rated oils are suitable only for engines produced before 1931, while SB-classed lubes work for engines built before 1951.

The rating follows the alphabet to show current statuses. Current acceptable grades start from SJ for engines built in 2001, all the way to SP for 2020-manufactured engines or the most recent.

For diesel motors, the grades start with the letter C, representing compression ignition, then another letter and -4. Similar to petrol engine oil grading, the system began with CA, which is oil-perfect for engines built before 1959, while CB is best for pre-1961 motors.

Current API diesel engine lubricant grades are CH-4, CI-4, CJ-4, and CK-4 for diesel motors manufactured from 1998. Additionally, there is the FA-4 rating, which solely applies to diesel engines built in 2017 and later, primarily over-the-road trucks.

API motor lubricant rating changes as years pass by, and reflect the evolution of engines and oil formulation technologies. It is advisable to get motor oil with the most recent grading, as they can support older engines.

10w30 Oil Explained

10w30 is a multigrade oil, with its viscosity rated at 10 for cold starts and 30 for normal and high operating temperatures. It is a versatile lubricant that you can use in old and new engines or warm and cold environments. It is the go-to lube for most modern vehicles.

When it’s cold, 10w30 motor lubricant will flow smoothly, and the engine will start without problems. This oil thickens when it gets hotter, meaning its protection capacity improves, and it will work well with heavy-duty and high-performance engines.

The kinematic viscosity of 10w30 motor oil varies from 9.3-12.5 cSt at 100⁰ Celsius (212⁰ Fahrenheit). Oils with a value near 9.3 perform better, especially when temperatures drop. 10w30 has a viscosity index of 146, which is crucial to its all-rounded performance.

This multigrade lubricant’s versatility is evident when you consider its vast operation temperature range of -25⁰ to 30⁰ Celsius (-13⁰ Fahrenheit to 86⁰ Fahrenheit). It can be synthetic, mineral, or blended and may have additives like detergent and anti-wear agents to improve its functionality.

How do 10w30 vs. 5w30 fare against each other? The two multigrade motor lubes have a similar flow rate at operating temperatures. The main difference is their performance when cold, with 5w30 flowing better than 10w30, as it is more resilient to icy surroundings.

Differences between SAE 30 and 10w30

SAE 30 and 10w30 vary in various ways, which determines their performance. Before analyzing the differences between the two engine oils, we can check out some of them, as summarized in the table below.

Element SAE 30 10w30
Viscosity index 97 146
Kinematic viscosity at 100⁰ Celsius/ 212⁰ Fahrenheit 9.3-12.5 cSt 9.3-12.5 cSt
Flash point 205⁰ Celsius 232⁰ Celsius
Additives Mostly has no additives Has plenty of additives, such as detergent, corrosion inhibitors and antiwear agents
Type of lubricant Mineral or synthetic Mineral, synthetic or synthetic blends
Application Primarily used for old engines or motors in lawnmowers and leaf blowers Mostly used in modern car engines

SAE 30 vs. 10w30 Viscosity

Viscosity is a crucial factor when deciding which type of oil to get. You can derive several takeaways from the SAE vs. 10w30 viscosity discussion, such as their similar kinematic viscosity at 100⁰ Celsius, of 9.3 to 12.5 cSt. You can see that both have an operating temperature density of 30, meaning you can use them in place of each other when it is hot.

Nonetheless, SAE 30 is a monograde lubricant, while 10w30 is multigrade, meaning the latter can flow effortlessly when cold. Furthermore, 10w30 has a higher viscosity index, meaning it experiences minimal changes with temperature increase, translating to resiliency.

Regarding their density, 10w30 is better than SAE 30 when you factor in their stability to change and versatility.

SAE 30 vs. 10w30 Generator

The oil you choose for your generator depends on several factors, such as the engine type and environment. On engine type, SAE 30 is ideal for heavy-duty generator engines, such as diesel engines. Diesel motors produce a lot of heat, and SAE 30 motor lube will be the best pick for this engine type due to its increasing thickness with temperature hikes.

On the flip side, 10w30 motor oil is perfect for petrol engines, providing an excellent flow rate even when temperatures fall. Talking about the environment, SAE 30 is ideal for high operating temperatures, where it becomes denser and more efficient in heat protection.

10w30 is more adaptable than SAE 30 as it works in cold and hot temperatures. Furthermore, 10w30 comes with plenty of additives like detergent that enhance its overall functionality.

SAE 30 vs. 10w30 Price

SAE 30 vs. 10w30 pricing is a common checkpoint for many people considering the two types of motor oil. SAE 30 is typically cheaper than 10w30, though the difference is minor. In the past, when 10w30 was still new in the market, the price difference was significant, prompting many people to go for the cheaper option.

The price of SAE 30 and 10w30 stretches depending on the brand, quantity, and retailer.

SAE 30 vs. 10w30 Lawnmower

As mentioned earlier, SAE 30 is commonly used for agricultural equipment such as lawnmowers, especially those with smaller or older engines. Both SAE 30 and 10w30 are excellent lawnmower oils, though their functionality varies depending on numerous things.

SAE 30 does a great job for lawnmowers, especially when working on your lawn during hot summers. 10w30 oil works fine when the weather is cold or warm, with a decent operating temperature range of -25⁰ to 30⁰ Celsius.

Unlike SAE 30, 10w30 motor oil has plenty of additives, such as detergent and corrosion inhibitors. These additives are crucial for engine health, helping prevent sludge buildup and boosting the durability of the components.

On the SAE 30 vs. 10w30 lawnmower weigh-up, you realize that most people who occasionally use their mowers will use SAE 30 motor oil. The lubricant is cheaper and perfect for one-time uses, especially during hot summers when many people mow their lawns.

SAE 30 vs. 10w30 Applications

SAE 30 is ideal for older engines, like those in vintage vehicles. It also works fine for smaller motors found in many agricultural utilities, such as lawnmowers, chainsaws, and lawn tractors. 10w30 engine oil is suitable for most modern engines.

When debating SAE 30 vs. 10w30 uses, you realize that 10w30 is more adaptable, as it works fine with older and newer motors. Additionally, it is a multigrade lubricant; thus, it supports the engine in various temperatures.  

What about SAE 30 vs. 10w30 pressure washer use? Most pressure washer manufacturers will recommend 10w30. Nevertheless, pressure washers have small engines, and SAE 30 oil will work fine with them.

Pick SAE 30 if you reside in warmer areas due to the lube’s characteristics when temperatures rise.

SAE 30 vs.10w30 Public Discussion

You can get an idea of SAE 30 and 10w30 functionality by referring to reputable public forums. Most discussions and reviews revolve around the interchangeability of the two oils, considering that both have a similar operating temperature viscosity of 30. This Quora review by Lee Morales touches on their exchangeable use.

On Lawn Site, a platform dedicated to lawnmower discussions, TPendagast, a user, contributes towards the SAE 30 vs. 10w30 topic by highlighting their pricing. The user talks about how popular SAE oil was in the past due to its relatively low pricing compared to 10w30 oil. However, 10w30 is now affordable, and many prefer it to its companion.

The Vintage Chevrolet Club of America (VCCA) online forum has a discussion focusing on the safety of 10w30 oil, introduced by 41specialdeluxe, an avid contributor. The conclusion is that you should buy products as suggested by your vehicle manufacturer or an experienced mechanic.

Related Queries

Are SAE 30 and 10w30 The Same?

SAE 30 and 10w30 motor oils are not the same: the former is a single-grade oil, whereas the latter is multigrade. SAE 30 is only good for operating temperatures and performs poorly when cold, as its viscosity increases.

The multigrade 10w30 is flexible, as it can serve you well when freezing or in regular operating temperatures. Despite their differences, you can notice they share the 30 suffix, meaning they have a similar high-temperature viscosity. You can use SAE 30 and 10w30 lubes interchangeably when it is hot.

Can I Use SAE 30 with 10w30?

SAE 30 and 10w30 have the same high or operating temperature viscosity, meaning they behave similarly when the engine gets warmer. You can use them in place of the other or mix them, but only for hot-temperature applications.

Many auto enthusiasts agree that mixing SAE 30 with 10w30 should be only a matter of necessity. The logic is that SAE 30 rarely has additives, while 10w30 has loads of them. Moreover, SAE 30 is unsuitable for most modern engines.

If you decide to mix them, you should ensure compatibility: mix synthetic oil with synthetic oil and the same for conventional lubricants. If possible, the oils should be from the same brand.

What is SAE 30 oil equivalent to?

Apart from the Society of Automotive Engineers (SAE), the International Organization for Standardization (ISO) is another body that tests and grades lubricants by viscosity. ISO’s oil grading relies on the oil’s kinematic viscosity at 40⁰ Celsius or 104⁰ Fahrenheit.

The rating begins with the letter ISO VG, with the VG standing for viscosity grade, followed by a number indicating the grade. The grades start from 10 to 6800, with the numbers denoting the oil’s midpoint viscosity at 40⁰ Celsius. ISO-tested and graded lubes will have tags like ISO VG 10, ISO VG 100, and ISO VG 6800, among many others.

SAE 30 has a kinematic viscosity of 90 cSt at 40⁰ Celsius. It shares this value with IS0 VG 100. If you cannot get SAE 30, look for a product with the ISO VG 100 tag, especially in Europe and other territories outside the USA.

Is SAE 30 Good?

SAE 30, like most engine care utilities, is good, provided it is appropriately used. You will get the best service from this engine oil if you reside in warm areas, offering better protection and sealing. It is a perfect lube for older and smaller engines.

The downside to this lubricant is its poor performance when it is cold. Icy conditions thicken the oil, affecting its flow rate. On top of that, SAE 30 typically lacks additives like detergent, making it unsuitable for new engines.

Can I Use SAE 30 Instead Of 10w30?

We finalize the SAE 30 vs. 10w30 discussion by focusing on their interchangeable use, a topic many are curious about. The two lubes have similar warm temperature viscosity grades, which allows for their reciprocal use when it is hot.

You can use 10w30 instead of SAE 30 in numerous settings courtesy of its versatility: the 10w30 flow rate is good when cold or hot. However, you should be keen when using SAE 30 instead of 10w30, as it is unsuitable for most new engines. SAE 30 lacks additives like detergent, a must-have for modern engines.

You can substitute 10w30 with SAE 30 for smaller engines, especially when it is hot.


Hi there, I am R. Hasan Tito, a mechanic, and owner of this website. My friend and I created this website to share our knowledge, expertise, and experience with our fellow mechanics' community and car users. I am a specialist and certified automotive mechanic (Both Heavy Commercial and Private Cars). I worked as a Mechanic and Mechanic Supervisor for over fifteen years at Global Rebound Automotive companies - Toyota, TATA, BMW, Nissan, TVs, and Others. Now, I enjoy my new role of leading a team of automotive experts (in their respective fields) and publish new content on a regular basis on my website and social media.

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