Update to oil change interval question: oil analysis results

[Elkins45]

This is a update to a thread where I asked how often occasional users change their oil. The thread is here: https://www.tractorbynet.com/forums...ing/408124-occasional-users-how-often-do.html

In order to find out if keeping the same oil in the tractor over multiple years was harmful I collected a sample when I changed the oil and sent it off to have it analyzed. Here’s a snapshot of the results for a sample of Kubota branded 15w-40 that had been run for about 80 hours over an interval of at least three years.



You wouldn’t expect to see much in the way of wear metals from an engine with less than 200 hours so the most important number here is the base number. As you can see, my three year old oil still has plenty of capacity left to neutralize acids and has no moisture contamination.

The bottom line here for me is that I don’t need to worry about changing oil based on the calendar date.

 

[mddorange]

Thanks for the report. I feel a lot better now that I didn't change my oil every year.

I put more than 80 hours on my tractor in three years so I changed it after three years. Glad to know that it was still good to go. :thumbsup:

 

[JOHNTHOMAS]

This is a update to a thread where I asked how often occasional users change their oil. The thread is here: https://www.tractorbynet.com/forums...ing/408124-occasional-users-how-often-do.html

In order to find out if keeping the same oil in the tractor over multiple years was harmful I collected a sample when I changed the oil and sent it off to have it analyzed. Here’s a snapshot of the results for a sample of Kubota branded 15w-40 that had been run for about 80 hours over an interval of at least three years.

View attachment 596061

You wouldn’t expect to see much in the way of wear metals from an engine with less than 200 hours so the most important number here is the base number. As you can see, my three year old oil still has plenty of capacity left to neutralize acids and has no moisture contamination.

The bottom line here for me is that I don’t need to worry about changing oil based on the calendar date.

Thanks for paying to document or provide more back up opinions which I have held and practiced for about 15 years with no real concern that I was wrong. I change them by Kubotas recommended hours of usage.
Many years ago I read where oil never breaks down per a molecular engineer but that it just gets dirty and once cleaned, use to be and probably still is resold and reused over and over and over.
Yep, I'm a big believer in filters. The molecular engineer was asked how often he changed his car engine oil and he said every 3000 miles since an oil change was so cheap.:laughing::cool2:

 

[shooterdon]

Great post....confirms my suspicions. I go by hours used as well.....and by miles on the vehicles

 

[diesel85]

I do this in all my equipment for decades. Never any issues.

Oil breaks down with use, generally not sitting.

I do hourly oil changes in my equipment. Some equipment will go 5 years without needing an oil change.

 

[Elkins45]

The WIX oil test kit was only $9.99 from Rock Auto, plus $4 to mail it to the lab. It was totally worth it to me to find out if I was doing any harm.

I bought two of them. I'm going to let my car go for 5000 miles and test it then. I have a sneaking suspicion that the 3000 mile oil change internal everyone recommends is way too frequent and all they are doing is wearing out their drain plugs.

 

[mcfarmall]

...all they are doing is wearing out their drain plugs.

That's a good one! I change my oil every 6 months in my vehicles and they still have a lot of life left in the oil. Tractor gets it once a year mainly due to the oil pan suffering from pinholes being eaten into it from the inside out. I suspect that it is acids from combustion and/or moisture in the oil from sitting.

 

[cat fever]

all they are doing is wearing out their drain plugs.

Hey, my truck drain plug resembles that remark!

My tractor gets an oil change every 100 hours regardless of how it was used.
Truck every 5000 miles. (Dodge Cummins)
Car every 10,000 miles. (this is what Audi recommends)
Harley every 3-5 thousand depends on where I'm at.

I've never had any kind of oil related engine problems so I'll keep doing what I'm doing.

 

[mddorange]

I'm going to let my car go for 5000 miles and test it then. I have a sneaking suspicion that the 3000 mile oil change internal everyone recommends is way too frequent and all they are doing is wearing out their drain plugs.

I have been waiting 5K miles to change engine oil for a long time without any problems.

 

[Doofy]

I made it 25,000 miles between changes on my company truck (1990 Chevy 2500). Always used Mobile 1 synthetic. Made it to 370,000 miles and blew the intake gaskets. It was repairable but a new Goodwrench engine was to cheap to pass up.