Appropriate oil for Generac Generator

[JD940]

Greetings, any help/advice would be greatly appreciated.

We just purchased a home with a Generac Home Generator that's fueled by propane. The instruction manual states-

"Use a high-quality detergent oil classified “For Service SJ or SH.” Detergent oils keep the engine cleaner and reduce carbon deposits. When changing the engine oil, be sure to use 5W-30 engine oil."

My first issue is with the SJ or SH. My research indicates that these are obsolete and that I am good with going with an SN but I want to be certain before I go dumping a new type of oil into generator. Second question is "Detergent oil". Is this simply referring to oil with additives?

Finally, any recommendations about a high quality, readily available oil to use that meets the above requirements?

Thanks!

 

[BISCUT]

I have had a Generac 16KW for a decade. I did an early break in and moved from Generac filters to a Fram TG and have used M1 0-40. Yearly oil change even though I know it isn't needed. I also put a cheapo hour meter on it.

Meanwhile my Honda walk behind mower gets M1 0-40 for 3 years Bas x x x x step child!

 

[MParr]

I would imagine that Generac 5W30 syn, Briggs & Stratton 5W30 syn and Shell Rotella T6 5W30 would be good choices. The Generac and Briggs oils are specifically formulated for air cooled engines.

 

[JimPghPA]

JD940, please provide the following information if you want the members to give you the best answers to what oil to use:

1) Is it an air cooled engine, or is it a water cooled engine ( does it have a radiator like a car with a radiator cap and hoses to and from the engine to the radiator?

2) What state and city are you located in? This may not sound important to you, but the oil requirements for a generator in Arizona and the requirements for a generator in Main are different.

3) If there was a long outage, would you be available to change the oil every 50 hours of running (every other day) or might you be away from home and the other people who live there not be knowledgeable about how to change the oil, and therefore the oil may ran for more than 2 days without changing?

 

[Donald]

Amsoil small engine oil should be good also. The air cooled engines are always a best effort at cooling. Cooling fins are a favorite place for mouses to build a nest.

 

[Captsunshine32724]

Greetings, any help/advice would be greatly appreciated.

We just purchased a home with a Generac Home Generator that's fueled by propane. The instruction manual states-

"Use a high-quality detergent oil classified “For Service SJ or SH.” Detergent oils keep the engine cleaner and reduce carbon deposits. When changing the engine oil, be sure to use 5W-30 engine oil."

My first issue is with the SJ or SH. My research indicates that these are obsolete and that I am good with going with an SN but I want to be certain before I go dumping a new type of oil into generator. Second question is "Detergent oil". Is this simply referring to oil with additives?

Finally, any recommendations about a high quality, readily available oil to use that meets the above requirements?

Thanks!

Congrats on being a prepared homeowner.

The SJ, and SH service levels were current at the time the unit was manufactured. Consider them the LOWEST quality oil you may use. Using the newest, SN or SP oils will provide better protection. "Detergent" oil is referring to the oil having additives to keep the engine clean, prevent rust etc. Some engines, i.e. newly rebuilt aviation engines are run on straight mineral oil(non-detergent), with no additives during the break in process. You would never want to use a straight mineral oil in your generac.

Its hard to argue with the engine manufactures recommendations in general. As mentioned above, any synthetic like Mobil 1 or any of the others will provide good protection in the 5W-30. I run both of my natural gas powered units on Pennzoil Syn 10-30 and have it stock piled in my garage for those extended runs we all enjoy down here in FL.

As mentioned, there are some oils out there, aimed at the motorcycle market that are specifically designed for air cooled engines. I think you would be fine with a good Synthetic 5w-30 from any of the major players. You didnt mention where you are located. Those gen sets had a few issues dealing with freezing temps in the past. Let us know if that could be a factor for you and we can get into that a little more.

 

[UncleDave]

something W30 will be fine.

I run my gensets in high ambient heat for long periods of time under relatively high load.
Been running M1 0W-40 in all my gensets for over a decade, and even in my water cooled diesels.
Its relatively cheap and easy to find.
Some run 24/7 for a week at a time getting hot fueled.

UD

 

[Gyro Gearloose]

The SJ, and SH service levels were current at the time the unit was manufactured. Consider them the LOWEST quality oil you may use.

SJ was the last API classification before the Zinc and Phosphorus levels started being limited. I suspect the small engine manufacturers recommend their own brand of SJ rated oil because it is blended with a full dose of additives and will provide a little extra protection for the half (90% ?) of the population that never changes small engine oil. Bitog members' maintenance habits, however, will allow other "options" that will produce at least an equal and possibly better long term outcome.

My small engines all get non-SN rated diesel oil for the extra additives.

 

[Astro_Guy]

It sounds as if you may have one of the larger generators with a water cooled engine. Personally I use M1 10w-30 HM or Rotella T6 5w-40 in my air cooled generators. As for the "SJ or SH" recommendations, those were the minimum specifications at the time of manufacture. You should be fine with newer rated oils.

 

[JD940]

JD940, please provide the following information if you want the members to give you the best answers to what oil to use:

1) Is it an air cooled engine, or is it a water cooled engine ( does it have a radiator like a car with a radiator cap and hoses to and from the engine to the radiator?

2) What state and city are you located in? This may not sound important to you, but the oil requirements for a generator in Arizona and the requirements for a generator in Main are different.

3) If there was a long outage, would you be available to change the oil every 50 hours of running (every other day) or might you be away from home and the other people who live there not be knowledgeable about how to change the oil, and therefore the oil may ran for more than 2 days without changing?

Thanks to everyone for the in-depth advice, very much appreciated!

1- Water cooled (Edit)
2- Birmingham, AL
3- I'm always home so oil can be changed every 50 hours during an outage.

 

[JD940]

Wow, thanks to everyone for the in-depth advice, I greatly appreciate it!!! I can now check one more headache off the new home checklist.

 

[mattwithcats]

Shell Rotella T6 in 5W+40...

post the oil filter, if it has one.

I will try and oversize it...

I ran a Wix 51516 in my Mom’s generator...

 

[JimPghPA]

+1 on the Shell Rotella T6 5W-40

It is available at a lot of places including WalMart in 5 Quart jugs for a good price. If there are any Tractor Supply stores near you they probably would have it for the lowest price.

 

[NormanBuntz]

Most Generac engines will use oil when run for extended periods, like after a hurricane or ice storm. That's one argument for using a 5w-40, especially in the summer. But by all means use a full synthetic. Conventional oils will burn faster in the air cooled engines that come in all Generac residential generators.

 

[Astro_Guy]

Thanks to everyone for the in-depth advice, very much appreciated!

1- Water cooled (Edit)
2- Birmingham, AL
3- I'm always home so oil can be changed every 50 hours during an outage.

It sounds to me as if automotive oil change intervals are more in order. 50 Hour OCI's are in the realm of the air-cooled world. 50 hours on a water cooled generator is a lot like 3000 highway miles on a car. 100 hours should be easy on just about any oil. 200 hours should easily be possible with any synthetic extended drain oil.

 

[linksep]

In Birmingham I would say any modern (SN, SN-Plus, or SP) 10w30 synthetic gas engine oil or Rotella T6 diesel oil in either 5w40 or 15w40. Change oil every year (or maybe two) if it only runs 15 minutes a week for "exercise"; during an extended outage check oil level every morning and change oil every 150 hours.

 

[repairman54]

7 yrs. now on my 2 cyl. 10k unit. Only 0-40 full synth. in it, usually M1. Unit see's -20f and below starts in it's north climate so a zero bottom number is a must as it's a weekend house. Gotta say that propane fuel sure keeps oil cleaner, longer than gasoline fueled.