Generac 5W20 Low Ash (GEO) oil for Generators

[cao-2000]

I searched BITOG, but couldn't find really find much on the Generac 5W20 oil, except this post which is more about Low Ash:

Low ash oil with propane engine

I have a little air cooled propane powered Generac standby generator. The manual basically says gasser 5w30 for year round temps. SN I believe. Pretty vague IMO. My first inclination is to run an A3/B4, but I’ve read a low ash oil is preferred for a propane engine. Is there any truth to this...

bobistheoilguy.com

In any case, I own an older 2008 10kW Generac wholehouse air-cooled generator on propane, and the manual specifies 5W30 oil for all temps.

The utility company recently paid for a new 2023 22kW air-cooled Generac generator on propane, and it seems now Generac recommends their own "Low Ash" 5W20 oil, specially designed for gaseous engines ("GEO" for Natural Gas & Propane), which tends to be very expensive. I have seen at almost $20 for 1 quart! But in bulk, I think you can get it for as little as $12 per quart, which is still high. I can't really seem to find any equivalent oil in other brands.

I know there is some debate on other forums whether to switch from 5W30 to Generac's own 5W20, or if "Low Ash", "GEO", etc. is just marketing. My post is NOT about these points. I have decided to use what Generac now recommends, and in the meantime do some additional research.

Being a cheapskate, I am thinking if I do a Blackstone or similar test, I might be able to find out who really makes this oil for Generac (or find a very similar formulation), and hopefully it can be bought for cheaper.

I saw the spreadsheet here on BITOG for Virgin Oil Analysis, and Generac isn't on there, so if I do the test I will update the spreadsheet and this post.

Mainly this post is for future reference of people wondering the same thing.

 

[MParr]

I have a 2020 Generac 22Kw that runs on propane. The manual states 5W30 Synthetic oil and that’s it. It doesn’t say anything about using low ash oil. The dealer told me any 5W30 Synthetic will do. However, they want folks to buy Generac filters and oil at a higher price.
Besides, most modern API automotive oils are low ash.

 

[nate379]

Delo HDAX NGEO or Delo 600 come to mind, but those are 15w40 or 40wt

 

[Astro_Guy]

I searched BITOG, but couldn't find really find much on the Generac 5W20 oil, except this post which is more about Low Ash:

Low ash oil with propane engine

I have a little air cooled propane powered Generac standby generator. The manual basically says gasser 5w30 for year round temps. SN I believe. Pretty vague IMO. My first inclination is to run an A3/B4, but I’ve read a low ash oil is preferred for a propane engine. Is there any truth to this...

bobistheoilguy.com

In any case, I own an older 2008 10kW Generac wholehouse air-cooled generator on propane, and the manual specifies 5W30 oil for all temps.

The utility company recently paid for a new 2023 22kW air-cooled Generac generator on propane, and it seems now Generac recommends their own "Low Ash" 5W20 oil, specially designed for gaseous engines ("GEO" for Natural Gas & Propane), which tends to be very expensive. I have seen at almost $20 for 1 quart! But in bulk, I think you can get it for as little as $12 per quart, which is still high. I can't really seem to find any equivalent oil in other brands.

I know there is some debate on other forums whether to switch from 5W30 to Generac's own 5W20, or if "Low Ash", "GEO", etc. is just marketing. My post is NOT about these points. I have decided to use what Generac now recommends, and in the meantime do some additional research.

Being a cheapskate, I am thinking if I do a Blackstone or similar test, I might be able to find out who really makes this oil for Generac (or find a very similar formulation), and hopefully it can be bought for cheaper.

I saw the spreadsheet here on BITOG for Virgin Oil Analysis, and Generac isn't on there, so if I do the test I will update the spreadsheet and this post.

Mainly this post is for future reference of people wondering the same thing.

Personally I cannot imagine running Xw-20 oil in any piece of air cooled OPE that is operated in temperate climates. My snowblower sees 5w-30 but eveything else runs (or will soon be running) 10w-30 or 15w-40. It's all about the HTHS when it copes to air cooled OPE.

 

[cao-2000]

No idea what Generac is doing, but here are the photos of the bottle.

 

[MParr]

Low Ash = Low SAPS

 

[mattwithcats]

I suggest Mobil 1 ESP in either
5W-30 (ACEA C3 rated)

Mobil 1™ ESP 5W-30| Mobil™

Discover how Mobil 1™ ESP 5W-30 advanced synthetic motor oil helps prolong the efficiency of emission systems in diesel and gasoline powered automobiles.

www.mobil.com

or
0W-20 (ACEA C5 rated)

Mobil 1™ ESP X2 0W-20 | Mobil™

Discover how Mobil 1™ ESP X2 0W-20 advanced synthetic motor oil can prolong the efficiency of emission systems in diesel and gasoline powered automobiles.

www.mobil.com

Both are light duty diesel rated, and I am running the ESP 0W-30 in my Saturn right now…

Understanding European Oil Standards: ACEA Specifications - Valvoline™ Global KSA - EN

 

[NormanBuntz]

Welcome to the forum. I'd bet that Generac's branded oil claims are based more on marketing than on science. I'm on my second Generac 16kw standby generator (2019 propane model), and I stick to 5w-30 synthetic and annual oil changes. My oil gets milky with the unit's biweekly exercise runs, but I've used 5w-30 synthetic since 2006 with no engine issues. Too bad Generac's interior stamped steel panels are so crappy that they rust as badly as an old Fiat.

 

[bpracer]

Im using Amsoil 5-30 Small engine oil. Its a specified for NG/Propane fuels.

 

[repairman54]

0-30w synth. in my 10k unit that sees -30 to 90f temps. No issues in 10 yrs now. If I wasn't in a sub zero winter zone 5-30w synth would do just fine. No way would I run a 5- 20w in an air-cooled unit in summer temps.
That bottle label is marketing bovine excrement.

 

[4WD]

Personally I cannot imagine running Xw-20 oil in any piece of air cooled OPE that is operated in temperate climates. My snowblower sees 5w-30 but eveything else runs (or will soon be running) 10w-30 or 15w-40. It's all about the HTHS when it copes to air cooled OPE.

Yeah - never thought I‘d see that … have owned 5 makes and they all call for 10W30 … use Redline in my WG9500DF …
Delvac 1 5W40 in others …

 

[cao-2000]

Generac claims their oil is a "Low Ash" formula. I am not sure if that means Low Ash in the virgin oil, or Low Ash in the used oil.

I am going back and forth with Blackstone Labs, and not sure the support person knows what they are talking about. I know I certainly am a noob.

Does anyone know if the Ash% test is needed, especially for a Virgin Oil Sample?

Standard Oil Analysis is $35, the Ash% adds another $55

 

[Big-Rich]

I'm in the process of buying a Generac 24KW generator (so far delivered but not yet installed) and my owner's manual (page 27) says it needs 5W20 full synthetic, low ash oil and they steer you hard toward their own "proprietary" oil.

I am not an oil expert like many of you seem to be but I'm sure you can help me. Please don't talk over my head if you know what I mean.

I found a site that lists many of the characteristics of Generac's "proprietary blend" and I'll post the listing here so you can help me find a substitute that is not nearly as expensive as at the Generac site. There is a table of characteristics of the Generac oil in the lower right of the picture but it doesn't help me find a viable substitute at a lower cost.

Is "low ash" and "for gaseous engines" the same thing (basically, for the same results)? Or can you buy an oil that says "low ash" but it's not for propane engines?

Can someone list a few substitutes that would meet the minimum criteria of the Generac engine for me?

For example, would (just an off the wall example) Valvoline Advanced Full Synthetic 5W-20 Motor Oil work or what criteria does it come up short for?

Robot or human?

Thanks for any pointers.

 

[cao-2000]

I forgot to update this thread. I had the Blackstone test done on the Virgin Generac 5W20, you can see the PDF in this thread:

VOA Database

Do you think when Generac says their oil is low ash, do they mean the virgin oil, or used oil? I assumed it meant virgin, but I'm new to understand oils. virgin, it will be a "low ash" out of the bottle.

bobistheoilguy.com

Hopefully that helps you.

FYI, all my other Generac generators specified 5W30 for all temps, with no mention of “low ash”.

I'm in the process of buying a Generac 24KW generator (so far delivered but not yet installed) and my owner's manual (page 27) says it needs 5W20 full synthetic, low ash oil and they steer you hard toward their own "proprietary" oil.

I am not an oil expert like many of you seem to be but I'm sure you can help me. Please don't talk over my head if you know what I mean.

I found a site that lists many of the characteristics of Generac's "proprietary blend" and I'll post the listing here so you can help me find a substitute that is not nearly as expensive as at the Generac site. There is a table of characteristics of the Generac oil in the lower right of the picture but it doesn't help me find a viable substitute at a lower cost.

Is "low ash" and "for gaseous engines" the same thing (basically, for the same results)? Or can you buy an oil that says "low ash" but it's not for propane engines?

Can someone list a few substitutes that would meet the minimum criteria of the Generac engine for me?

For example, would (just an off the wall example) Valvoline Advanced Full Synthetic 5W-20 Motor Oil work or what criteria does it come up short for?

Robot or human?

Thanks for any pointers.
View attachment 205677

 

[Cujet]

I suggest Mobil 1 ESP in either
5W-30 (ACEA C3 rated)

0W-20 (ACEA C5 rated)
Both are light duty diesel rated, and I am running the ESP 0W-30 in my Saturn right now…

Both would work well, as they are low calcium oils. As are many oils today.

Interesting that Generac goes for 0W-20. The must manage oil temps well to achieve and acceptable margin of protection in air cooled engines. The advantage is obvious, fast flow during cold startup.

0W-20 is not a good choice when oil temps reach 260ºF. But works quite well in high stress applications where oil temps are kept below 200, sometimes at 180.

 

[cao-2000]

Both would work well, as they are low calcium oils. As are many oils today.

Interesting that Generac goes for 0W-20. The must manage oil temps well to achieve and acceptable margin of protection in air cooled engines. The advantage is obvious, fast flow during cold startup.

0W-20 is not a good choice when oil temps reach 260ºF. But works quite well in high stress applications where oil temps are kept below 200, sometimes at 180.

Minor correction. Generac seems to be recommending 5W20 in the newer literature vs 5W30 in the older, at least for the air cooled stuff. I haven’t seen 0W20 recommended by them, but I have only seen a few manuals.

And they specifically recommend their magic “low ash” blend (at a very high cost).

 

[Cujet]

Minor correction (s)

I was a little distracted writing that post, it was a quickie. Grammar took a hit too.

 

[NormanBuntz]

I've had a Generac 16kw standby generator for 18 years, and I do my own service. I say that Generac promoting its "exclusive" low ash formula is baloney.

 

[MParr]

Minor correction. Generac seems to be recommending 5W20 in the newer literature vs 5W30 in the older, at least for the air cooled stuff. I haven’t seen 0W20 recommended by them, but I have only seen a few manuals.

And they specifically recommend their magic “low ash” blend (at a very high cost).

Yep, the new recommendation is 5W20. I’ll stick with the old recommendation on mine. As far as the “low ash” bunk, any API SP Synthetic will meet that requirement.

 

[repairman54]

Low ash, it is not a 2 stroke boat motor. I could see using a 0-20w in the artic though.