Oil change and fuel filter change interval low mileage

[Ljwt330]

Originally Posted by Wild Card

No Cummins does not accept oil analysis in lieu of oil change.

New emmisions engines eat alot of carbon/soot. If your putting 5-10k miles a year on your engine I would change it yearly. If your putting 5-10k miles in 6 months I would change it semi annual. If your only putting a couple thou a year I would change it every 2

I would contact Cummins for the 6mo to 12mo change in intervals

These guys relying on an oil analysis company to tell them the oil is good for another x amount of miles are putting a lot of faith in their hands. Oil analysis for wear patterns and irregularitys for predictive maint. But for me to run extended oil drain intervals on a $30k engines at the blessing of some guy at a lab...no thanks. Oil is cheap...

Again these new engines are soot eating monsters. Anything from EPA 04 EGR to present EGR/DPF/SCR engines. Change the oil frequently. Dont like it take your old oil and fuel receipts to your local congessman set it on his desk and ask him how this crap is benefiting the universe.

I have been following this thread out of interest, and I believe the above posts provides a context that must be considered--the emissions system, or lack thereof, of the engine.

Many responses came from owners with early engines with few, if any, emission systems. Those would certainly not have the issues with oil contamination that engines equipped with EGR, DPF, and DEF might have. The newer the engine, the more critical "clean" oil becomes.

Keeping that in mind, engines under warranty are the type the above post references and require much more compliance with recommended service. Out of warranty engine owners must consider the type of emission systems installed, and decide whether or not to continue the recommended services based on some analytical data, such as an oil analysis, or their own preemptive approach.


In short, there is no broad brush answer for all diesel engines.

[Monacoach]

I talked to a diesel mechanic today who told me that he would not bother changing the oil until our next big trip in Dec 2020.

[US1]

Food for thought.... A while back on another forum I hang around on, a discussion of frequent oil changes came about. 1 individual claimed studies have shown it better to once a month, suck out 1 quart of oil, and install a fresh quart, than to change the oil at the recommended 12 month intervals. Seems crazy, until you really think about it.

For discussion purposes, consider a regular SBC motor that takes 5 qts of oil and a 12 month oil change cycle.

All fresh oil at a full change, then drive it unchanged for 12 month. So at the end, you have 5 qts of 'dirty' oil.
But if you start off with full fresh oil, then in a month, suck out and replace 1 qt with fresh oil. The oil at that time is 1/12 'used', but now you have replenished 1/5 of it with new. So in all reality, the oil in the pan as a whole is now better than 1/12 used at the 1st month, and each month the quality is bumped back up some and it can never reach ' a full used' status. Keep in mind, I'm just trying to relay the procedure and the reasoning.

While I used a SBC as an example for easy math, I believe the real situation was related to cargo ships, or the likes that have a huge oil resorvoir.

[Wild Card]

Originally Posted by US1

Food for thought.... A while back on another forum I hang around on, a discussion of frequent oil changes came about. 1 individual claimed studies have shown it better to once a month, suck out 1 quart of oil, and install a fresh quart, than to change the oil at the recommended 12 month intervals. Seems crazy, until you really think about it.

For discussion purposes, consider a regular SBC motor that takes 5 qts of oil and a 12 month oil change cycle.

All fresh oil at a full change, then drive it unchanged for 12 month. So at the end, you have 5 qts of 'dirty' oil.
But if you start off with full fresh oil, then in a month, suck out and replace 1 qt with fresh oil. The oil at that time is 1/12 'used', but now you have replenished 1/5 of it with new. So in all reality, the oil in the pan as a whole is now better than 1/12 used at the 1st month, and each month the quality is bumped back up some and it can never reach ' a full used' status. Keep in mind, I'm just trying to relay the procedure and the reasoning.

While I used a SBC as an example for easy math, I believe the real situation was related to cargo ships, or the likes that have a huge oil resorvoir.

5qts of dirty oil, suck one out and add 1 new...ya still got 5 qts of dirty oil

[US1]

Originally Posted by Wild Card

5qts of dirty oil, suck one out and add 1 new...ya still got 5 qts of dirty oil

It would appear so on the surface, but remember, you can never have 5 qts of dirty oil, unless you do the once a yr oil change. Then it starts off off fresh, and degrades every day for 12 months.
I just used those numbers for ease of discussion. As I said, it appears crazy, until you really think about it. Gotta look past the normal initial line of thinking and think about the math and what is really transpiring.

[HJLowell]

Originally Posted by US1

Food for thought.... A while back on another forum I hang around on, a discussion of frequent oil changes came about. 1 individual claimed studies have shown it better to once a month, suck out 1 quart of oil, and install a fresh quart, than to change the oil at the recommended 12 month intervals. Seems crazy, until you really think about it.

For discussion purposes, consider a regular SBC motor that takes 5 qts of oil and a 12 month oil change cycle.

All fresh oil at a full change, then drive it unchanged for 12 month. So at the end, you have 5 qts of 'dirty' oil.
But if you start off with full fresh oil, then in a month, suck out and replace 1 qt with fresh oil. The oil at that time is 1/12 'used', but now you have replenished 1/5 of it with new. So in all reality, the oil in the pan as a whole is now better than 1/12 used at the 1st month, and each month the quality is bumped back up some and it can never reach ' a full used' status. Keep in mind, I'm just trying to relay the procedure and the reasoning.

While I used a SBC as an example for easy math, I believe the real situation was related to cargo ships, or the likes that have a huge oil resorvoir.

Back in the 50s we had vehicles that used a quart of oil every 100 to 200 miles.
We carried 2 , 5 gallon buckets of oil at all times.

We never ever even thought of changing the oil.

In 64, I rode from Lafayette to the Indy for sprints on Friday night then the Indy 500 with h.S. friends.
The friends father drove his family chevy and he was a mechanic at the John Deere store for some 45 year's.
He used the 5 gallon pail down and back.
He laughed.
When I get time I need to do a valve job.
We all tractor pulled, flora, Monticello, Attica lacerne, peru
Frankfort and Indy.
He helped us win many a pull.

[red300zx]

Originally Posted by Monacoach

Just wondering when others would change their oil and fuel filters after one year but only 700 miles. I'm guessing most would change everything based on the one year?

Cummins engineers recommend you change the oil at listed mileage or annually if milage is not met. There opinion is 300 or 15000 pay me now pay me later. Cummins should go 500-750+ k before major work with minimal PM.

[Monacoach]

Originally Posted by red300zx

Cummins engineers recommend you change the oil at listed mileage or annually if milage is not met. There opinion is 300 or 15000 pay me now pay me later. Cummins should go 500-750+ k before major work with minimal PM.

We all know what the engineers recommend . It is not an exact science. . I was looking for opinions of you every day hands on rv owners.

[grindstone01]

Originally Posted by Monacoach

We all know what the engineers recommend . It is not an exact science. . I was looking for opinions of you every day hands on rv owners.

Engineers test their engines under different conditions, situations, and it is a very exact science as to what is best for their engine. The actual RV owners may think they know what is better based on a limited sample and will believe they are doing the best thing, until their engine begins to have problems. Then it's "oh Crap", who can we blame!!
Do you question a doctor's recommendations and instead seek medical opinions from forum posters?

[Winemaker2]

As you can see answers all over the lot and all will likely claim they are more correct.
Best answers are...
If in warranty do what the manual recommends
If out of warranty have it tested and you decide what you are comfortable with.

[red300zx]

Originally Posted by grindstone01

Engineers test their engines under different conditions, situations, and it is a very exact science as to what is best for their engine. The actual RV owners may think they know what is better based on a limited sample and will believe they are doing the best thing, until their engine begins to have problems. Then it's "oh Crap", who can we blame!!
Do you question a doctor's recommendations and instead seek medical opinions from forum posters?

Yes they test to destruction under every possible conditions and yes it is a science. That is why they test the same failure multiple times to see if they can find the point of failure that is repeatable. The guy is a friend and I'm pretty sure he wouldn't have me spend 300 bucks if it wasn't necessary.

[Monacoach]

So the science is one year is ok but the very next day your engine is in jeopardy even though the oil tests ok? I dont think the engineers are accounting for rvs that sit otherwise they would have to post several oil change intervals depending on specific circumstances. Easier for them to have one general guideline and let us figure it out based on our own usage.

[grindstone01]

Originally Posted by Monacoach

So the science is one year is ok but the very next day your engine is in jeopardy even though the oil tests ok? I dont think the engineers are accounting for rvs that sit otherwise they would have to post several oil change intervals depending on specific circumstances. Easier for them to have one general guideline and let us figure it out based on our own usage.

So you don't believe that engineers thought about the possibility of a RV/engine sitting stationary for a period? Used oil will turn acidity after a period. I have rebuilt antique farm tractors that sat 20 years with used oil in them and the crank shaft would be pitted/ruined from the effects of acid oil. (extreme example here)
I will bet they did simulate a 1000 mile oil sitting for 6 months and their test results determined that a oil change based on a time limit is necessary.
Please by all means, do what you feel is logical to you, after all it is now your motor and you are responsible going forward, not the engine manufacture once the warranty is expired.
At least get a oil sample done so you have some knowledge as to the oils health/life and you will be able to make a partially informed decision.

[96 Wideglide]

Originally Posted by grindstone01

I will bet they did simulate a 1000 mile oil sitting for 6 months and their test results determined that a oil change based on a time limit is necessary.

I'll bet they didn't !!