Which oil to use in an air cooled engine

[nfinch86]

Went to Wally World today and got the t6 rotella it's 5w-40 not 15-40 . It was 23 and change for a gallon.

I put the 5w 40 T6 Rotella in my Ranger yesterday & it is running nice & smooth with plenty of power !!!!!!!

Norm

[Aeronca41]

I was looking at a jug of Rotella T6 synthetic 5w-40 yesterday and was surprised to see an SM rating on it along with the diesel ratings. I had heard that it was the step to SM that took out the zinc, so it made me wonder if it is adequate for air cooled engines. Also heard that the zinc limits only apply to viscosities 10w-30 and below, which may explain why the T6 is still OK. Can anyone shed any light on this? I have been using QS Defy, but would switch to a synthetic for better protection. And, is a 5w-40 synthetic ok in an Onan in 90-100 degr F temps? All thoughts appreciated.

[cruizer]

Sm rating doesn't mean much, maybe a drop like 200 parts per million drop. Still has lots of zinc and Phousphous

[Aeronca41]

Thanks, Cruizer! REALLY appreciate your knowledge and willingness to share it with all of us!

[ryanjones2150]

What's the SM mean?

[nfinch86]

What's the SM mean?

Cruizer , said in the above post - SM has a Drop of 200 parts per million drop in the Zinc levels.

Norm

[H80N]

API Engine Oil Service Category Charts

SM

Introduced on 30 November 2004

Category SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving. They may be used where API Service Category SJ and SL earlier categories are recommended. http://www.oilspecifications.org/api_eolcs.php

[H80N]

API CHART

http://www.api.org/~/media/files/oil...0210.pdf?la=en

[ryanjones2150]

I was thinking it was an abbreviation for something. Probably why a Google search just brought up a bunch more two letter tags without an associated two word definition. You guys are super smart. I have no idea where that would fall into API terms.

[ryanjones2150]

Ok, for an Onan generator in an RV, the Onan shop sells onamax 15w-40 for my unit. The bottle doesn't say diddly squat about zinc and all that other stuff you guys are talking about. But it has a bunch of those letter designators...CJ-4, CI-4 plus, CI-4, CH-4, CG-4, CF-4, CF/SL<br />
<br />
Any of that good? I also got some rotella T triple protection...but the bottle on that doesn't say anything about the good stuff and it has a bunch of letters too. <br />
<br />
I went looking for the rotella T6 in a 15w-40 but my local parts source doesn't carry it and isn't sure if it's available. <br />
<br />
My RV is less than a year old and this is my genset first oil change at 66 hours. What say you gents?

[nfinch86]

Ok, for an Onan generator in an RV, the Onan shop sells onamax 15w-40 for my unit. The bottle doesn't say diddly squat about zinc and all that other stuff you guys are talking about. But it has a bunch of those letter designators...CJ-4, CI-4 plus, CI-4, CH-4, CG-4, CF-4, CF/SL<br />
<br />
Any of that good? I also got some rotella T triple protection...but the bottle on that doesn't say anything about the good stuff and it has a bunch of letters too. <br />
<br />
I went looking for the rotella T6 in a 15w-40 but my local parts source doesn't carry it and isn't sure if it's available. <br />
<br />
My RV is less than a year old and this is my genset first oil change at 66 hours. What say you gents?

Ryan - Going by what H80N posted above. From what I can gather the CJ-4 & SM are what we are looking for.
Click on the the links & read them - Good info. A little tedious ,but interesting .I bought the Rotella T6 - 5w - 40 locally here. It's the synthetic version, which is all I've ever used in all my machines. ( Welder, Compressor, & Truck. )

Norm

[ryanjones2150]

Thanks Norm. The Onan and rotella I got are both CJ-4. I haven't had the time to sit and read through the technical stuff on that link. You know how it goes, sometimes more in a day than hours to do it.

[Kpack]

What model is your onan and is it still under warranty ?

[nfinch86]

Thanks Norm. The Onan and rotella I got are both CJ-4. I haven't had the time to sit and read through the technical stuff on that link. You know how it goes, sometimes more in a day than hours to do it.

I hear ya, Ryan.
But if you have the time, it's a good but tedious read.......... lol.

Good info.
If you can find the Rotella T6, which is the synthetic form, it has All the Good stuff, as far as I can figure.......... LOL.

Maybe try Wal-Mart, here in Canada, we have a place called Canadian Tire which has everything from soup to nuts...........lol.

Norm

[ryanjones2150]

It's a KY model 4kw Onan. It is under warranty still. <br />
<br />
...soup to nuts eh? But do they have tires?