Just found Shell Rotella T-4 SAE15w40, will that work? Probably not as it's for diesel engines and a syn blend, right?
Also found 10w40 available for gas engines but says for high mileage cars.
* This post was edited 07/01/18 09:11am by DAS26miles *
This is the Onan oil versus temp chart.
![[image]](https://i.imgur.com/VUvmKXrl.jpg)
Clay (WA5NMR), Lee (Wife), Katie & Kelli (cats) Salli (dog).
Fixed domicile after 1 year of snowbirding and eleven years Full Timing in a 2004 Winnebago Sightseer 35N, Workhorse chassis, Honda Accord toad
I can explain it to you.
But I Can Not understand it for you !
....
Connected using T-Mobile Home internet and Visible Phone service
1997 F53 Bounder 36s
DAS26miles wrote:
Wish I could find 30w.
Wish I could find 30w.
Did you check Amazon?
Proud father of a US Marine
Kevin
Small aircraft engine Air cooled
Generator limited RPM
Aircraft limited RPM
Generator sees wide temperature range
Aircraft sees wide temperature range
Generator can see much hotter metal temps
Aircraft can see much hotter metal temps
The big difference is ASH content of the oil
Onan used to make an uproar about ash content with Onan engines using LPG
Question: Is the newer API service J or service K oils as low in ash as aircraft oil? If there was no difference then why does Lycoming insist on low ash engine oil. This area should be explored. There is something to it.
ksg5000 wrote:
If memory serves me correctly Onan service guys use Rotella - I use that if it's available. Not a big believer that brand means much so long as you change your oil on a regular basis.
I once asked my mechanic what oil I should use in my pickup. He said, "Anything but Pennzoil." Interestingly, I had been using Pennzoil in my Chevy 454 MH, when the engine blew. Coincidence???
If memory serves me correctly Onan service guys use Rotella - I use that if it's available. Not a big believer that brand means much so long as you change your oil on a regular basis.
DW and Me
2016 Riverside White Water Retro 195
2014 Nissan Titan SL Crew Cab
Formerly, I used to work for the department of redundancy department.
Life in Black and Blue
DAS26miles wrote:
I used to use Pennzoil 30 in my Winnebago ...
I used to use Pennzoil 30 in my Winnebago ...
Modern multi-viscosity oils (10W30, 10W40, 15W40) Are MUCH better than any single weight oil ! Brand really does not matter as they are all tested to meet the API standard.
suprz wrote:
I use Rotella 15W40 that's what the rv dealer used when I picked up the RV and just changed the oil and again used the same.
I use Rotella 15W40 that's what the rv dealer used when I picked up the RV and just changed the oil and again used the same.
That is what I wpuld use also.
Full synthetic seems to be available in 5w-30, 10w-40, but not 15w-40 except in some diesel oils. That's OK, but do you really want to buy 5 gallons?
Our temps run a little lower, so I think full syn 10w-40.
Remember that owner's manuals don't morph to the latest info as oils improve and are tested. I found an owner's manual for 4KY up to Spec P, which has got to be pretty recent, and the oil chart was the same as above. I also checked to make sure we were looking at specs for the air-cooled 3600 rpm ONANs, and we were. I'd imagine their liquid cooled and diesel generators might have different specs.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB
Amsoil synthetic small engine oil
2021 Toyota Tundra TRD Off Road double cab
2022 Airstream International 27FB
Blue Ox Sway Pro hitch
M.I.L is self quatanting in Jacksonville Zoo
Rotella T4
theoldwizard1 wrote:
Modern multi-viscosity oils (10W30, 10W40, 15W40) Are MUCH better than any single weight oil ! Brand really does not matter as they are all tested to meet the API standard.
That is what I wpuld use also.
DAS26miles wrote:
I used to use Pennzoil 30 in my Winnebago ...
I used to use Pennzoil 30 in my Winnebago ...
Modern multi-viscosity oils (10W30, 10W40, 15W40) Are MUCH better than any single weight oil ! Brand really does not matter as they are all tested to meet the API standard.
suprz wrote:
I use Rotella 15W40 that's what the rv dealer used when I picked up the RV and just changed the oil and again used the same.
I use Rotella 15W40 that's what the rv dealer used when I picked up the RV and just changed the oil and again used the same.
That is what I wpuld use also.
Same here.
punomatic wrote:
..."Anything but Pennzoil." Interestingly, I had been using Pennzoil in my Chevy 454 MH, when the engine blew. Coincidence???
..."Anything but Pennzoil." Interestingly, I had been using Pennzoil in my Chevy 454 MH, when the engine blew. Coincidence???
My wife's mom bought a new Buick and had it serviced at the dealer, who proudly used Pennzoil. She bought another Buick and gave the first one to us. We ran it quite awhile, but it got to running poorly and had a valve train noise. I found the oil pump and timing set were worn out. Damage on the camshaft sprocket led me to pull the camshaft. That particular engine has sprocket integral with shaft. At that point, found the noise was a flat spot worn on a cam lobe.
To replace cam and lifters, intake manifold/valley cover had to come off. That's when I found the interior of the block covered with a thick black cinder-like crust. Pulled oil pan and the inside of the bottom end of the block was full too. Removed with scraper and shop vac plus spray parts cleaner. Pennzoil deposits! The Cam wear? Timing set wear? Lubrication failure? Just saying. The process may have changed, but you could pour Pennzoil and when the last pretty golden fluid had flowed, there'd be a black trace, maybe a tar. Enough to give Pennzoil a bad name. Some shy away from Quaker State, being another Pennsylvania Crude product. These were from the dino oil days, doubt any of this applies to synthetics.
Have used various brands, doesn't seem to be an issue as long as a premium brand name.
2010 Suncruiser
MEXICOWANDERER wrote:
Onan Generator Air Cooled
Small aircraft engine Air cooled
Generator limited RPM
Aircraft limited RPM
Generator sees wide temperature range
Aircraft sees wide temperature range
Generator can see much hotter metal temps
Aircraft can see much hotter metal temps
The big difference is ASH content of the oil
Onan used to make an uproar about ash content with Onan engines using LPG
Question: Is the newer API service J or service K oils as low in ash as aircraft oil? If there was no difference then why does Lycoming insist on low ash engine oil. This area should be explored. There is something to it.
Onan Generator Air Cooled
Small aircraft engine Air cooled
Generator limited RPM
Aircraft limited RPM
Generator sees wide temperature range
Aircraft sees wide temperature range
Generator can see much hotter metal temps
Aircraft can see much hotter metal temps
The big difference is ASH content of the oil
Onan used to make an uproar about ash content with Onan engines using LPG
Question: Is the newer API service J or service K oils as low in ash as aircraft oil? If there was no difference then why does Lycoming insist on low ash engine oil. This area should be explored. There is something to it.
Comparing the similarities of Onan air cooled genny oil to aircraft piston engine oil is interesting, but, its where they differ that's important. (and WILL KILL YOU) One: Most aircraft piston engines still use 100LL avgas which contains tetraethyl lead (octane enhancement) and methylene/ethylene dibromide. (scavenging agent) Onan gennys use 87 octane unleaded gas. Two: Aircraft piston engines require oil changes every 50 hours compared to 150 for the gennys. Three: Aircraft piston engines are designed to burn oil and oil consumption is expected.
Aircraft engines require ashless oil because when metal containing dispersants were first used, there were an excessive number of fatal engine failures due to clogged oil systems, detonation, and insoluble deposits in the ring land areas leading to engine failure. (and more) These failures were attributed to excessive deposits from oil burning.
The failures were not attributed to: "My mommy told me that . . ., My mechanic said that . . ., My brother in law said that . . ., I read on the internet that . . . ., it goes on forever. They were attributed to actual field research by people who KNOW what they are doing and have the overwhelming science to support it. What a novel idea!
Ashless Dispersant oils do not contain ash. They minimize ash generation when burned in the combustion environment. Kind of like a log on a campfire does not contain ash. Ash forms as a chemical reaction in the fire pit as the wood burns.
Suffice to say: Follow the oil change recommendations in your owners manual regarding oil for your Onan genny, and you'll be fine. And MEX, you've got to cut out those afternoon naps. API SN has been current for a few years now and is about to be updated. Newer automotive oils (API SN) do generate less ash when burning due to changes in the dispersant and the extreme pressure wear additive chemistry. In the automotive industry they were mainly changed to improve catalytic converter efficiency.
See: http://www.pqiamerica.com/apiserviceclass.htm
Chum lee