Are you looking for the best oil for your generator? Do you have questions like: What kind of oil does a generator take? or Should I use 10W-30, 5W-30 or SAE 30 oil?
I have great news for you! Our team here at Generatorist has helped over 600,000 visitors find the ideal type of oil for their generator and we will help you as well.
Did you know that generators use the same motor oil, that you use for your car?
In most cases, you will need an SAE 10W-30 oil type. The 10W-30 oil from Honda (1,767+ Reviews) is the best one in this category, but it’s pricey. We think that it is the best fit for most generators.
For cheaper alternatives, check out Valvoline VR1 Racing (725+ Reviews) or Castrol Motor Oil (465+ Reviews). They offer the same performance for a better price.
Keep reading this article to learn about the best oil for your generator in various weather conditions, as well as the most trusted brands we recommend.
Let’s start with the tip number 1:
LOOK INTO YOUR USER´S GUIDE
The first step in our shopping guide is to consult the User’s Guide or Owner’s Manual you got with your generator. You will find every piece of information you will ever need inside, so don’t throw it away.
From our personal experience, information about the required engine oil is usually in the maintenance section of your manual.
If you can’t find the manual for your generator, feel free to use these tools from Generac, Honda, Yahama or Champion Power Equipment to download one for your specific model or check out the best oils for Predator generators & Generac generators here on Generatorist.
Moreover, here is our guide for changing the oil in your generator with videos for the most popular brands of generators out there, go check it out as well.
Keep in MIND THE oil Viscosity
The most crucial feature you need to pay close attention to while choosing the engine oil for your generator is its viscosity. As mentioned above, you can find the recommended type in the Owner´s Guide or Manual.
In most cases, you will need an SAE 10W-30 oil type. The 10W-30 oil from Honda (1,767+ Reviews) is the best one in this category, but it’s pricey. We think that it is the best fit for most generators.
Here is our detailed comparison of 10W-30 oil vs 5W-30 oil, the second most recommended type of oil for generators.
For cheaper alternatives, check out Valvoline VR1 Racing (725+ Reviews) or Castrol Motor Oil (465+ Reviews). They offer the same performance for a better price.
The SAE acronym in the name of motor oil refers to the grading system developed by the Society of Automotive Engineers. The rest of the code refers to the oil’s viscosity at different temperatures.
The first number in the code, in this case the 10W, means how well can this oil be pumped at cold temperatures. The W refers to the word winter (not the weight).
The second number in the code means how well can the oil be pumped when heated to 212 degrees Fahrenheit (100 degrees Celsius) or higher.
Also, you should select a good quality detergent oil bearing the American Petroleum Institute (API) service classifications SJ, SL, SM, or SN.
However, always double-check the correct type of oil in your user’s manual and don’t rely solely on our recommendations. It may differ from one type of generator to the other.
If you use a different type of oil than the recommended one, you may cause premature wearing of individual engine parts.
CONSIDER operating TEMPERATUREs
Another thing to consider while choosing the best oil for your generator is the temperature of the environment where you will be using it. This has been also pointed out in every User Manual we have seen.
Here is an excellent graphic that we have found in one manual:
If you are going to use your generator in a very cold environment that allows only for very low starting temperatures, then the Synthetic 5W-30 may be a better option for you.
However, you need to keep in mind that this oil comes with an increased oil consumption by the engine at higher operating temperatures so check its level before each use.
According to the experts from Generac, you should keep these recommendations in mind:
“Above 32°F (0°C), use SAE 30. Below 40°F (4.4°C) and down to -10°F (-23°C), use 10W-30. Synthetic 5W-30 can be used in all temperatures. Oil should be changed after the first 20-30 hours of operation and every 100 hours of run time thereafter.”
Let’s sum up the best generator oils for specific weather:
- Above 32°F (0°C) – SAE 30 – Briggs & Stratton Engine Oil (1222+ Reviews)
- 40°F (4.4°C) down to -10°F (-23°C) – 10W-30 – Honda Motor Oil (1,767+ Reviews)
- All temperatures – Synthetic 5W-30 – Generac Full Synthetic Motor Oil (91+ Reviews)
Know the type of your engine
Another thing you should consider before deciding which oil is good for your generator is to know whether the engine inside is a 2-stroke or a 4-stroke engine.
From our experience, there is only a small number of generators using a 2-stroke engine and a vast majority of generators use a 4-stroke engine.
Each type of engine requires a different kind of oil.
While in a 4 stroke engine you use oil and fuel separately, in a 2-stroke engine, you can either mix fuel and engine oil in a recommended ratio by yourself or you can purchase a pre-mixed solution.
Here are the bestselling oils for 2-stroke engines on Amazon:
- Echo Power Blend 1 Gallon Oil Mix (346+ Reviews)
- Husqvarna XP+ 2 Stroke Oil (117+ Reviews)
- Husqvarna HP Synthetic 2-Cycle Oil (194+ Reviews)
Go for reliable brands
Last but not least, you should never try to save on engine oil for your generator. Preferring a lower price instead of a high-quality product may cause a lot of worries later.
Rather invest a little bit more into reliable brands, such as:
- Honda
- Onan
- Briggs & Stratton
- Shell Rotella
- Motor 1
- Generac
- Craftsman
We believe that all these brands are reliable and produce only high-quality products. If you want to get your supply of high-quality oils for a decent price, then take a look at Amazon.com deals.
Just keep in mind that different generators may need different types of engine oil.
Our top picks among oils
| TOP SAE 10W-30 | TOP SAE 15W-40 | TOP SAE 5W-30 | TOP 2-STROKE | TOP SAE 30 |
|---|---|---|---|---|
|
|
|
|
|
| Honda Motor Oil | Shell ROTELLA | Generac FS Oil | Husqvarna XP+ | Briggs & Stratton |
| Mineral Oil | Synthetic Blend | 100% Synthetic Oil | Synthetic Blend | Mineral Oil |
| SN (API class) | CK-4 (API class) | SN (API class) | TC (JASO FD) | SJ (API class) |
| 4-Stroke | 4-Stroke | 4-Stroke | 2-Stroke | 4-Stroke |
| Check Price | Check Price | Check Price | Check Price | Check Price |
HONDA OIL
Advantages:
- Well-known brand
- Meets / exceeds SN API
- Quick lubrication
Specification:
- SAE 10W-30
- API SN
- Non-synthetic
Our top selection in the SAE 10W-30 category of engine oils is the Honda Genuine Oil. This high quality engine lubricant has been created for power equipment and tools that have 4-cycle engines.
It is classified as an SN oil according to the American Petroleum Institute (API).
This means that this oil is one of the best available these days. Not only that, choosing a high quality oil such as Honda for your generator will make your engine run more efficiently, hence you will reduce your fuel consumption and save some money.
Although this oil is excellent, it is expensive (it costs almost the same as full synthetic oil). That is the reason why a lot of people decide not to get it.
Don´t forget to check out the feedback and reviews of Amazon customers. Focus on those classified as “verified purchase”.
Other good SAE 10W-30 options:
Shell Rotella OIL
Advantages:
- Well-known brand
- Exceeds highest API class
- Low oil breakdown
Specification:
- SAE 15W-40
- API CK-4
- Synthetic blend
Another type of oil that is recommended in Owner´s Manuals (although rarely) is the SAE 15W-40. If you need this type of oil, then our recommendation is to go for Shell ROTELLA T5.
This product is a synthetic blend that combines synthetic base oils with advanced additives.
Such a blend is perfect especially for diesel engines where resistance to increased heat and stress is required. Also, this oil is classified as CK-4 or better according to the American Petroleum Institute (API).
This is the best rating for oil used in diesel engines. The best part is, that Shell ROTELLA ensures triple protection against wear, deposits, and oil breakdown at high temperature oxidation.
The best part? This oil is not very expensive compared to other 15w-40 options.
Don´t forget to check out the feedback and reviews of Amazon customers. Focus on those classified as “verified purchase”.
Other good SAE 15W-40 options:
gENERAC mOTOR OIL
Advantages:
- Created for generators
- Exceeds highest API class
- Protects against deposits
Specification:
- SAE 5W-30
- API SN
- Synthetic blend
Another type of oil that is very often recommended by Owner´s Manuals is the SAE 5W-30. This oil is perfect for generators that will be used in slightly colder climates as it ensures an easier start and better viscosity at lower temperatures.
Our best choice in this category is the Full Synthetic motor oil by Generac. This brand is well known in the market for portable generators as they produce a lot of portable and standby machines.
As the name suggests, this is a synthetic oil that has been fortified with advanced additive technology.
It meets the highest API SN classification (also ILSAC GF-5).
Not only that, this oil has been deliberately manufactured for gasoline generators to provide maximum protection against viscosity breakdown.
Also, it protects against the formation of sludge and varnish deposits on individual parts of your engine.
Although this Generac SAE 5W-30 oil is great, engines in generators that are running in warmer climates may have increased oil consumption.
Don´t forget to check out the feedback and reviews of Amazon customers. Focus on those classified as “verified purchase”.
Other good SAE 5W-30 options:
hUSQvarna XP+
Advantages:
- Excellent for 2-cycle engines
- Low operating temperatures
- Low smoke formula
Specification:
- 2-Stroke oil
- JASO-FD certified
- Synthetic blend
Although a vast majority of generators use 4-stroke engines, there are some machines with “old-school” 2-cycle engines. If you own one and need a new oil for it, then go for Husqvarna XP+.
Husqvarna is a well known manufacturer of small machines utilizing 2-stroke engines so they have a lot of experience with formulating the proper oil as well.
This semi synthetic oil is JASO-FD certified so it meets the latest standards and requirements.
Not only that, Husqvarna XP+ includes a fuel stabilizer, and provides for low operating temperatures, leading to better engine protection and lower smoke. Luckily, this oil is still on the affordable side.
Don´t forget to check out the feedback and reviews of Amazon customers. Focus on those classified as “verified purchase”.
Other good options for 2-stroke engines:
Briggs & Stratton
Advantages:
- Good for warmer temperatures
- Warranty certified
Specification:
- SAE 30 type of oil
- API SJ/CD classified
- Mineral oil
The second most often recommended oil in Owner´s Manuals I had an opportunity to look into is SAE 30. If you have a 4-cycle engine in your generator, then you may try Briggs & Stratton small engine oil.
It has been specially created for use in all Briggs & Stratton generators. Also, this oil is a high-quality detergent oil that has been classified as SJ/CD by the API.
If this oil is good enough for engineers from Briggs & Stratton, then it is a good choice for us too.
This oil provides good lubrication and engine protection at a moderate price. The best part? This oil is proudly made in the USA.
Don´t forget to check out the feedback and reviews of Amazon customers. Focus on those classified as “verified purchase”.
Other good SAE 30 options:
Can I use a different BRand of oil In my Generator?
We get lots of questions about whether it’s a good idea to mix different brands of oils. There are a few things you should keep in mind before you do so.
One of the first steps is to check out your manual and look for instructions like: Is there a recommended oil of a specific brand and viscosity or is there only a certain weight mentioned?
If there is a specific brand and viscosity mentioned, stick to that recommendation.
When there is only a weight of oil recommended in the manual, stick to the top-tier brands mentioned in this guide and pick a viscosity that is suitable for your weather.
What Could happen when I use too little or too much oil?
Both of these options will affect your engine in a bad way. When you add too much oil, you can increase the resistance of your engine.
What is more, if the oil is at an incorrect pressure, the lubrication of engine parts won’t be optimized and that will cause increased wear.
You can experience oil leakage as well in this scenario and trust me, this isn’t good.
On the other hand, too little oil will activate the low-oil alarm and will give a shorter runtime. An adequate amount of oil is responsible for cooling and cleaning as well.
When the oil level is too low, you can burn the engine and that will be the worst scenario, don’t you agree?
What's the difference between single-grade and multi-grade rating?
For example SAE 30 oil is a great example of a single-grade rating. It describes the weight of oil in warm temperatures, which affects the oil viscosity as we mentioned earlier in this guide.
The drawback of this rating system is that it doesn’t describe the exact features of oil at all temperatures.
On the other hand, multi-grade rating like 10W-30 oil reflects the oil properties much better. Number 30 in this rating describes the same features as in the SAE 30, which is the weight of oil in warm temperatures.
The number 10 stands for the oil viscosity in winter (W) conditions.
How often should I change the oil in my generator?
The main idea for changing the oil at regular intervals is to make your generator last as long as possible and avoid unnecessary damage.
The best place to look for information regarding ideal intervals is your generator’s manual. You will find there plenty of useful information and the correct maintenance schedule.
The general rule is to change the oil after the first 20-30 hours of operation and every 100 hours of run time thereafter. With synthetic oil, you can double the run time to 200 hours.
Some generators are equipped with a run time meter, for some generators you will need to keep track of hours manually. When you are not sure of the ideal interval, just remember this:
You can’t go wrong with changing the oil sooner rather than later.
Can I use Synthetic Oil in A Generator?
Yes, it is possible to use synthetic oil in your gas generator. In theory, this type of oil should provide better coating, but this is seen only in motors with overhead valves.
Using synthetic oil is safe for your generator. In the past there were some issues with overheating in small engines when they were first introduced. Nowadays they are completely safe.
For example, the most popular producer of generators – Honda, offers this advice:
“Honda engines are developed, tested and certified with petroleum based motor oils as a lubricant. Synthetic oils may be used; however, any motor oil used in our engines must meet all oil requirements as stated in the owner’s manual.
In addition, recommended oil change intervals must be followed.”
The main disadvantage of using synthetic motor oils in your generator is the price. These oils are much more expensive than conventional oils, but for their longevity, they are hard to beat.
Our top picks among oils
| TOP SAE 10W-30 | TOP SAE 15W-40 | TOP SAE 5W-30 | TOP 2-STROKE | TOP SAE 30 |
|---|---|---|---|---|
|
|
|
|
|
|
| Honda Motor Oil | Shell ROTELLA | Generac FS Oil | Husqvarna XP+ | Briggs & Stratton |
| Mineral Oil | Synthetic Blend | 100% Synthetic Oil | Synthetic Blend | Mineral Oil |
| SN (API class) | CK-4 (API class) | SN (API class) | TC (JASO FD) | SJ (API class) |
| 4-Stroke | 4-Stroke | 4-Stroke | 2-Stroke | 4-Stroke |
| Check Price | Check Price | Check Price | Check Price | Check Price |
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Matthew Gerther
Founder, Generator enthusiast
Our aim here at the Generatorist is to become the No. 1 resource for all things related to generators & your power needs. We have helped over 600,000 visitors with our tips, articles and reviews and we will help you as well.
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7 thoughts on “Choosing the Best Oil for Your Generator: Shopping Guide & Tips”
I have a new ALP 1000 watt generator that is propane use only. The owners manual doesn’t really specify an oil other than saying 4 cycle that meets or exceeds SG and SF ratings suitable for temps in my area. Via email, they said basic 10-40 or 20-50 good enough, which doesn’t line up with your article. I am in Tennessee. We have some cold sub freezing temps in winter but hot and humid in summer. What would you recommend? This article seems to say synthetic 5W-30 is best all around for all temperatures.
Hey Timothy, thanks for stopping by and leaving your comment.
Sadly, to provide you with a more specific answer, I would need to know at least a city in Tennessee, where you are going to use your generator as the average temperature may differ significantly in each region.
I have looked at the climate data for Tennessee and based on those numbers, you should be fine with the 10W30. Just see this table for temperature range & oil usage.
However, if they didn’t say anything about synthetic oil, I would stick to the regular 10W30 as otherwise, this could give them a cause to void the warranty if you need any repairs. Just keep in mind that your generator may consume 10W-30 more easily at higher summer temperatures so don’t forget to check and top off the oil often if you go with that option.
By the way, the best approach is to use 10W-30 or even 5W-30 oil in winter and then change it for 10W-40 or 20W-50 before summer. However, it isn’t as comfortable & economical as using one type of oil all-year-long.
Hello,
I’m building a sound inhibiting generator enclosure that will live in our back yard. It is a westinghouse 12500 dual fuel. there is insolation in the enclosure as well as forced air inlet/outlet for temp control. I am trying to find a product that would work as a muffler or “silencer” as some are calling it. Do you have any advice?
Thanks,
Bob
Can I use a non detergent 30 weight oil in my generator?
NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I use Kohler 10w30 Syn Blend W/extra zinc in my Kohler powered 725cc Cub lawn tractor here in the deep south. Is it ok to use the same oil in my Ultra Source Generac 990cc generator? Also both are OHV so do both engines have flat tappets? Thank you.
Hello,
Am Nwaneriaku, Collins from Nigeria. I hold B.Sc in Technical and Science Education, Mechanical Option.
I’m glad coming in contact with your write-ups here. I will appreciate if you educate me on big and small generators. How to identify them, the types of oil to be use for big and small generator , when to use the oils and why. Will want to know a little or in detail how to maintain generators.
Thanks so much.
Best regards. .
Nwaneriaku,C.O