The SAE 30 Oil Guide (What It Is + 13 FAQs) (2023)

You may have heard of (and are likely using) SAE 5W-30 or SAE 10W-30 motor oil.

These are engine oil viscosity grades designed by the SAE (Society of Automotive Engineers), which is why you see “SAE” appended before the grade.

But what about SAE 30 oil?
Is SAE 30 oil the same as 5W-30 and 10W-30 oil?

Don’t worry.
We’ll take a closer look at what SAE 30 motor oil is, what it’s used for, and answer some questions on this oil.

This Article Contains

  • What Is SAE 30 Oil?
  • What Is SAE 30 Oil Used For?
  • 13 SAE 30 Oil FAQs
    • What Is A Viscosity Rating?
    • What Is SAE 30 Equivalent To?
    • What’s The Difference Between SAE 30 And SAE 40 Oils?
    • Is SAE 30 Oil The Same As 10W-30?
    • Is SAE 30 The Same As SAE 30W?
    • Is SAE 30 Non Detergent Oil?
    • Is SAE 30 A Marine Engine Oil?
    • Is SAE 30 Synthetic?
    • Can I Use 5W-30 Instead Of SAE 30?
    • Can I Use SAE 30 Oil In Diesel Engines?
    • Can I Mix SAE 30 Oil With 10W30 Oil?
    • Can I Use SAE 30 In A Lawn Mower?
    • Does SAE 30 Oil Have Additives?

Let’s get started.

What Is SAE 30 Oil?

The SAE 30 oil is a single grade oil with a viscosity rating of 30.

It’s called a single grade (or monograde) oil because it only has one viscosity grade. This is different from a multi grade oil, like 10W-30, which is rated for both SAE 10W and SAE 30.

A single grade oil can be rated for a hot viscosity grade or a cold-start viscosity grade (where it’ll have a “W” suffix, standing for Winter). In a multi grade oil, the winter grade viscosity emulates the engine crank at cold temperatures.

The SAE 30 oil is rated only for hot viscosity.
This rating indicates how viscous the motor oil is at an operating temperature of 100OC (212OF).

Why is this important?
Temperature has a direct impact on viscosity.

(Video) Engine Oil Codes Explained, SAE (Society of Automotive Engineers) numbers - Oil Viscosity Explained

If an engine heats up beyond certain temperature thresholds, the motor oil will experience thermal breakdown and start to degrade. You’d want to avoid this as sufficient engine lubrication is key to ensuring long engine life.

Next, let’s see where you’d use SAE 30 motor oil.

What Is SAE 30 Oil Used For?

The SAE 30 motor oil is typically used in small engines like a small tractor, snow blower, or lawn mower.

And while most modern engines in passenger vehicles today use the multi grade oil variety, you’ll still find some four-stroke gasoline engines (like those in powerboats, motorcycles, or older cars) calling for SAE 30.

Now that we know more of the SAE 30 oil, let’s move on to some FAQs.

13 SAE 30 Oil FAQs

Here’s a collection of SAE 30 oil FAQs and their answers:

1. What Is A Viscosity Rating?

Viscosity measures the flow rate of a fluid at a particular temperature.

The Society of Automotive Engineers defines engine oil viscosity ratings from 0 to 60 in the SAE J300 standard. A lower grade generally indicates a thinner oil, and a higher rating is for thicker oil. Winter grades have a “W” appended to the number.

2. What Is SAE 30 Equivalent To?

The SAE and ISO (International Standards Organization) use different scales to measure viscosity.

For comparison:

(Video) Lawn Mower Oil Guide: What Type of Lawn Mower Oil Should I Use? |

  • SAE 30 is equivalent to ISO VG 100
  • SAE 20 is equivalent to ISO VG 46 and 68
  • SAE 10W is equivalent to ISO VG 32

Note: ISO VG is short for International Standards Organization Viscosity Grade.

SAE viscosity grades cover engine crankcase and gear oils.
ISO grades are comparable to the SAE, and include others like the AGMA (American Gear Manufacturers Association) grades for gear oils.

3. What’s The Difference Between SAE 30 And SAE 40 Oils?

SAE 40 oil is a slightly thicker oil than SAE 30 and will thin out slower at high temperatures.

4. Is SAE 30 Oil The Same As 10W-30?


Unlike SAE 30, SAE 10W-30 is multi grade oil. SAE 10W-30 has SAE 10W viscosity at a lower temperature and SAE 30 viscosity at a hotter operating temp.

5. Is SAE 30 The Same As SAE 30W?

There is no SAE 30W (which is a cold temperature grade) in the SAE J300 standard.

Only SAE 30 is available, which refers to a hot viscosity rating at 100OC.

6. Is SAE 30 Non Detergent Oil?

SAE 30 is typically a non detergent motor oil used in small engines.

Detergent oils contain special additives designed to trap and suspend dirt and dissolve engine oil sludge in the oil until it’s changed. A non detergent oil doesn’t have these additives.

A non detergent motor oil will usually be marked as such. So, any motor oil that isn’t marked as non detergent is a detergent blend by default.

(Video) Car Engine Oil In a Lawnmower? 'Explained' - Best Engine Oil & Lawnmower Oil

7. Is SAE 30 A Marine Engine Oil?

SAE 30 motor oil and SAE 30 marine engine oil are different things.

Though oil in a four-stroke marine engine does the same thing as in an automobile engine, marine and passenger vehicle motor oils aren’t interchangeable.

Marine engines are often cooled by lake, sea, or river water. So, while they’re controlled thermostatically, their temperature cycling is different from a road-going automobile.

Marine engine oil needs to handle high RPMs and the constant load experienced by marine engines. They require a corrosion inhibitor that can better resist moisture and rust compared to automotive engine oil.

These oils also often go past their oil change window, so antioxidants are critical to extending oil life and providing a long engine life.

8. Is SAE 30 Synthetic?

SAE 30 motor oil can be synthetic oil or otherwise.

Here’s the difference:
Synthetic oil is an oil type, while SAE 30 is an oil grade.

9. Can I Use 5W-30 Instead Of SAE 30?

Both oils have a “30” hot viscosity rating.

This means SAE 5W-30 oil has the same flow rate as SAE 30 at operating temp. So, technically it’s fine to use SAE 5W-30 oil in place of SAE 30.

10. Can I Use SAE 30 Oil In Diesel Engines?

SAE 30 motor oil is specified for use in some older 2-stroke and 4-stroke diesel engines.

(Video) What Is The Best Oil For Lawnmowers | Small Engines

Before using the SAE 30 oil, make sure to check which Diesel Engine industry classification is needed — like API CK-4 or API CF-4. This should be indicated on the oil bottle.

Note: API (American Petroleum Institute) “S” classifications are for gasoline engines (not diesel engines) like API SN or SP.

11. Can I Mix SAE 30 Oil With 10W-30 Oil?

API requires all engine oil to be compatible with each other. This means you can mix any SAE graded motor oils.

You might see SAE 30 oil specified for an older engine, like those in classic cars. However, modern engines typically require multi-grade oils, so using an SAE 30 motor oil in any vehicle built recently would be inadvisable. Always check the owner’s manual first!

12. Can I Use SAE 30 In A Lawn Mower?

SAE 30 oil is the most common oil for small engines. It’s often recommended for lawn mower engine use. To be sure, always check the lawn mower owner’s manual first.

13. Does SAE 30 Oil Have Additives?

Many engine oils, including SAE 30 oils, have additives to improve engine performance and enhance engine protection and lubrication.

A single grade oil like SAE 30, however, cannot use polymeric viscosity index improvers.

Final Thoughts

Motor lubricants and grease play an essential role in keeping the internal engine components running smoothly, whether it goes in your car, snow blower, or lawnmower.

As a result, using the correct lubricant is highly important.
You don’t want to damage your engine from unnecessary heat and grinding. Not only will that reduce your engine efficiency, but it will also cut short your engine’s life.

As for your car, keep an eye on your motor oil consumption and make sure the oil level is good. The best way to do this is to stick to a regular maintenance schedule, easily done with mobile mechanics like RepairSmith!

RepairSmith is available seven days a week, offers easy online booking, and a 12-month | 12,000-mile warranty for all repairs. Just contact them, and their ASE-certified mechanics will drop by to help in no time!

(Video) Castrol 5W-30 oil explained | Which oil for my car? | Castrol U.K.


What does SAE 30 mean for oil? ›

SAE 30 Meaning

These are monograde oils which are mainly used at temperatures above freezing point. SAE 30 oils do not have good cold flow properties. Use them only in spring, summer and autumn. The number '30' refers to the kinematic viscosity at 100 °C.

What oil can I use instead of sae30? ›

Both oils have a “30” hot viscosity rating. This means SAE 5W-30 oil has the same flow rate as SAE 30 at operating temp. So, technically it's fine to use SAE 5W-30 oil in place of SAE 30.

What is the full form of SAE 30? ›

SAE stands for Society of Automotive Engineers. The SAE developed a numerical classification system to define the viscosity or thickness of oil. The original viscosity grades were all mono-grades, e.g. a typical engine oil was a SAE 30. This was an operating temperature viscosity.

What is the upper limit for an SAE 30 oil at 100 degrees? ›

Oils with SAE viscosity grades ending in 30 have a viscosity between 9.3 and 12.5 m²/s at 100 degrees Celsius with an HTHS viscosity (high temperature high shear) of 2.9 mPa.

How long is SAE 30 oil good for? ›

five years. Just keep it away from long-term exposure to extreme heat, and keep it sealed up so it isn't constantly exposed to air or have the chance to develop condensation. Your oil will last longer on the shelf than you think it will.

What does SAE standard mean? ›

Those are recommended practices from SAE International, a group that issues engineering standards across various industries. SAE originated in the early 1900s as the Society of Automobile Engineers but soon became the Society of Automotive Engineers, a move that reflected its growing influence beyond the automobile.

What viscosity is SAE 30? ›

Automotive Lubricant Viscosity Grades: Engine Oils – SAE J 300, Dec. 1999
SAE Viscosity Grade[°C]Min. Viscosity [mm²/s] at 100 °CMax. Viscosity [mm²/s] at 100 °C
6 more rows

What happens if you mix hydraulic oil with engine oil? ›

Doing so could compromise the additive performance of both constituents, cause corrosion of component surfaces and lead to increased mechanical wear.

Is SAE 30 synthetic? ›

Sierra SAE 30 is a full synthetic marine engine oil with performance additives.

What does SAE mean on oil? ›

SAE, the acronym for the Society of Automotive Engineers, is responsible for establishing a classification system based solely on oil viscosity. To classify the oils, their viscosity is measured in cold conditions at different temperatures below zero, and then in hot conditions at 100ºC.

What is SAE oil used for? ›

Engine oil grades like SAE 5W30 oil or 10W40 are commonly used (for diesel or gasoline engines) because they're thin enough to flow at a low temperature (regions with colder temperatures) but thick enough to perform well at a higher temperature.

What is the specific weight of SAE 30 oil? ›

Specific gravity is simply the ratio of the specific weight of a given liquid to the specific weight of water at 4° C (γwater = 9.81 kN/m3 or 62.4 lb/ft3).
©Kurt Gramoll.
20°C (68°F) 1 atmDensity, ρ
SAE 10W Oil8701.688
SAE 30W Oil8911.729
SAE 50W Oil9021.750
12 more rows

How do you know how much oil to add to the top? ›

To get an idea of how much oil you need; the gap between the marks on the dipstick usually represents around 1 litre of oil, so you know that if your oil mark was at the minimum, you need around a litre to top it up. If it's only halfway down, you probably need around half a litre.

What oil level percentage is too low? ›

If the readout drops to 5% it means that the oil has become so dirty that it needs to be changed immediately before it drops even lower. Indeed, once it reaches 0%, you have not only reached the point where service is past due, but also the point where the remaining oil is probably doing more harm than good.

What happens if you exceed max oil level? ›

Too much oil in the engine can also cause the pressure on the crankshaft to increase, causing oil to enter the exhaust pipe from the crankshaft into the combustion chamber, blocking the combustion chamber hole with oil and eventually clogging the engine. Wet spark plug; excess oil will also flood the spark plug well.

Can expired oil still be used? ›

How to Know if Oil Has Gone Bad. Most oils don't have an expiration date, but have a “best by date”, instead. This means you can still use the oil, but it may not be at peak quality. And it is likely safe to consume as long as it tastes and smells fresh.

What temperatures is SAE 30 Good For? ›

SAE 30 has been rated for hot viscosity. That means that while it might work in your car in cold weather, there have been no tests to prove it. It will reach its viscosity peak at around 212℉ but will break down once the engine temperature reaches 250-260℉. After that point, the engine will overheat.

Does old oil go bad? ›

A short answer to this question is yes. Motor oil can only last for a certain period of time. That's why it comes with an expiry date. For this reason, oil goes bad with time just by sitting in the engine.

How do I read a SAE standard? ›

Carbon steels and alloy steels are designated a four digit number, whereby the first digit indicates the main alloying element(s), the second digit indicates tg (top grade) element(s), and the last two digits indicate the amount of carbon, in hundredths of a percent (basis points) by weight.

What is the SAE system of measurement? ›

Standard American English and the Metric System

Today, measuring in feet and inches is part of the Standard American English (SAE) or Imperial units of measurement, along with volumes like gallons and fluid ounces and weights like pounds. It's standard in the United States and two other countries in the world.

What is SAE approved? ›

SAE (Society of Automotive Engineers)

In short, SAE guides the quality of the product and the DOT tests the product to make sure it is fully compliant with transportation law and approved for use on all US roads and highways.

What is the temperature range of SAE? ›

Therefore, the SAE has developed two separate viscosity measurements, one at cold temperatures and one at high temperatures. The most common temperatures in the high temperature range are 40°C and 100°C.

Does it matter what oil I put in my lawn mower? ›

While automotive engine oil, such as 10W-30 or 10W-40, can be used in a lawn mower engine, it is generally recommended that SAE 30 motor oil be used.

Is SAE 30 the same as 4 stroke oil? ›

The standard oil used for 4-stroke engines found on petrol lawnmowers is grade SAE 30. Synthetic variations include SAE 5W-30 and SAE 10W-30.

Is power steering fluid same as hydraulic oil? ›

Power steering fluid is the hydraulic fluid used in the steering system to create a hydraulic link between the steering wheel and the front wheels. That decreases the amount of effort required to turn the wheels. Power steering fluid also lubricates the moving parts within the steering system.

Can I use wd40 on hydraulic? ›

By using the following steps & products, you can ensure that your hydraulic lifts function for many years: To prevent the pipes, hidden underside metallic areas from rust & corrosion, apply a generous layer of WD-40 Multi-Use Product. WD-40 MUP not only helps in removing rust but also prevents rust accumulation.

Can I use ATF instead of hydraulic fluid? ›

Most hydraulic systems will operate satisfactorily using a variety of fluids. These include engine oil, automatic transmission fluid and oil formulated specifically for the hydraulic compartment.

How often should the oil filter be changed? ›

Many manufacturers recommend that the oil filter be replaced every second time you get your oil changed. So, if you're on a 3,000-mile cycle you'd change your filter every 6,000; if you're on a 6,000-mile cycle (as with most modern vehicles) you'd change out every 12,000.

Can SAE 30 be used in a lawn mower? ›

SAE 5W-30 is a multigrade engine oil with a low viscosity to flow better at colder temperatures (than 10W-30), but protect the engine enough in heat. Synthetic SAE 5W-30 is a synthetic (artificial) lawn mower oil that works for both cold and warm weather.

Can you put SAE 30 in a car? ›

I would not recommend using SAE 30 in anything other than a lawnmower. It's a mono grade and has very limited additives. It's too thick when cold, it won't flow quickly enough for full protection,these days it's produced in small volumes so the costs are now as high or higher than a modern multi grade.

Does oil get thicker when hot? ›

So does that mean as the oil gets hotter, it gets thicker? Nope – other way around! Motor oil gets thinner as it's heated, but to prevent it from getting too thin at higher temperatures, additives (viscosity modifiers) are used so that it behaves like a thicker grade oil at higher temps.

How can you tell if oil is synthetic? ›

The easiest way to tell whether your vehicle requires conventional or synthetic oil is to check the car's owner's manual. There will be a page (either in the printed or online version) that describes the exact oil type recommended by the manufacturer.

How often should you check your oil? ›

You should check your oil level at least once every couple of weeks or before a long journey and in older cars, maybe even more.

How long does SAE oil last? ›

Expiry Date

Synthetic oil and synthetic blend oil will last about 7-8 years, and maybe even longer. If you cannot find the expiry date, make sure you use up any half-opened or unopened motor oil bottles within 2-5 years of the manufacturing date.

What happens if you mix SAE and synthetic oil? ›

So, can you mix synthetic oil with regular oil? Yes. If it's something you do only occasionally, mixing shouldn't damage your engine. Let's say you want to top off your oil, just to keep you rolling until your next regularly scheduled maintenance check.

What do numbers on oil mean? ›

You might be familiar with terms such as “30-weight” or “10W-30” oil. Those numbers refer to the grade. The higher the number, the thicker the oil. The lower the number, the thinner. Thinner oils flow faster than thicker oils, and engineers design engines to work with a certain grade of oil.

Is SAE 30 for small engines? ›

SAE 30 - Warmer temperatures, most common oil for small engines.

How do you know if oil is too full? ›

What happens if I put too much oil in my car?
  1. Oil leakage.
  2. The burning smell of engine oil.
  3. Smoke coming from the engine.
  4. Smoke releasing from the exhaust tailpipe.
  5. Engine making strange noises.

What happens if your oil is a little over full? ›

When too much oil is added, the level in the oil pan becomes too high. That allows a fast-moving lobed rod called the crankshaft to come into contact with the oil and essentially aerate it. The result is a foamy, frothy substance that cannot properly lubricate the engine.

How many miles can you go on 15% oil life? ›

You should get between 750 and 1125 miles of range from 15% oil life. This is based on the pure assumption that a single oil change is required every 5,000 to 7,500 miles.

How urgent is low oil level? ›

Driving with too low of an oil level can saddle you with serious problems. Your car engine will continue to run even if it has very little oil in it. However, eventually, the oil will run out and your engine will start to function less efficiently. The moving parts will no longer have a fluid barrier between them.

At what percentage should oil be changed? ›

If the oil level is low, the remaining oil degrades much quicker. It's always the last thousand miles, or running low on oil, that oil sludge develops. Once it is there, it can not be removed without an engine rebuild. Summary: I wouldn't go past 20% oil life remaining.

How much oil overfill is ok? ›

If the oil level is a little above the full mark, that shouldn't cause problems. If it's overfilled by half a quart or more, or foam shows on the dipstick, the best fix is to have the oil drained and refilled to the proper level.

How many miles can a car go over the oil change limit? ›

Cars can generally go 5,000 to 7,500 miles before needing an oil change. Furthermore, if your vehicle uses synthetic oil, you can drive 10,000 or even 15,000 miles between oil changes. Continue reading to learn more about oil changes or skip to scheduling your oil change right here on our website.

How long can you drive with high oil level? ›

Generally speaking, you have about 2 weeks or 500 miles of driving before a flashing oil light turns into a legitimate problem. But once it hits that point, things can go downhill fast, leading to serious mechanical damage. So, try to get your vehicle into a mechanic sooner rather than later.

Is SAE 30 and 10w30 the same? ›

10w30 is thinner than SAE 30. The “30” means that it has the same viscosity as the other when the engine is hot. However, since it is thinner, it will never become as thick as SAE 30 when it gets cold. 10w30 has a viscosity of 10w which means it will start moving and protecting engine parts at a colder temperature.

Can I use 10w30 with SAE 30? ›

SAE 30 oil is a common choice for warmer weather, while people often use 10w30 oil in colder weather. While you can mix these oils, it's best not to as it could damage your mower engine. Also, if the oils are from different manufacturers, it's best not to mix them.

Is SAE 30 full synthetic? ›

Sierra SAE 30 is a full synthetic marine engine oil with performance additives.

Can I replace SAE 30 with 10w30? ›

You're fine using either SAE 30 oil or 10W30 oil for either type of appliance. Although one type may be more effective for certain models of lawnmowers and generators than the other, they will generally both work.

What is the best oil to use in my lawn mower? ›

SAE 30 - Warmer temperatures, most common oil for small engines. SAE 10W-30 - Varying temperature range, this grade of oil improves cold-weather starting, but may increase oil consumption. Synthetic SAE 5W-30 - Best protection at all temperatures as well as improved starting with less oil consumption.


1. Can you mix SAE 30 and 10w30?
(Ask About MOVIES)
2. Diesel Engine OIL In Small Engines Experiment Test
3. WARNING Mechanics DO NOT USE this engine oil? Mobil1, Pennzoil, Castrol
4. Will Thinner Oils Damage Your Engine?
(Engineering Explained)
5. What Does SAE Stand For & SAE Oil Viscosity Grade Mean?
(Synthetic Oil Protection)
6. Don't Destroy Your Engine With Bad Motor Oil
(Petroleum Quality Institute of America)
Top Articles
Latest Posts
Article information

Author: Sen. Ignacio Ratke

Last Updated: 04/01/2023

Views: 6474

Rating: 4.6 / 5 (56 voted)

Reviews: 95% of readers found this page helpful

Author information

Name: Sen. Ignacio Ratke

Birthday: 1999-05-27

Address: Apt. 171 8116 Bailey Via, Roberthaven, GA 58289

Phone: +2585395768220

Job: Lead Liaison

Hobby: Lockpicking, LARPing, Lego building, Lapidary, Macrame, Book restoration, Bodybuilding

Introduction: My name is Sen. Ignacio Ratke, I am a adventurous, zealous, outstanding, agreeable, precious, excited, gifted person who loves writing and wants to share my knowledge and understanding with you.