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Oil change interval confusion

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Rustymayes

RVF VIP
Joined
Sep 11, 2022
Messages
228
Location
Vacaville, CA
RV Year
2022
RV Make
Newmar
RV Model
4081
Fulltimer
No
I have a 2022 Dutch Star 4081 with a Cummins L9 450 HP power plant. The owner's manual has a service interval chart that has different milage between oil changes depending on MPG. At 5 to 7 which is what I experience the book recommends up to 30,000 miles or 1500 hours or 18 months. I have always changed the oil on my cars and boats at 12 months regardless the mileage or hours. What do you guys typically do? I have not had to add any oil since I bought the rig back in October. I have under 6000 miles on it. The coach was built in February of 2022 but I have no idea when it was actually put into service by being driven to the west coast to the dealership. Thanks for the input.
 
On my 6.7 Cummins I use a 7500 mile interval. That will easily get me across the country and back so I can always do my oil changes at home. Cummins says 15,000 but the thing works hard and I consider just driving it normally to be “severe duty” so that’s what I do. It holds 18 quarts. If it had greater capacity I might push it to 10,000. If you want to get scientific about it use an oil analysis service - I’ve always thought that would be interesting but have never done it. I just figure more frequent oil changes are cheap insurance (around $120 and about a half hour of labor). If I had an ISL I’d probably push it to 10k.

Maybe next time I’m at 7500 I’ll try this: Free Test Kits | Blackstone Laboratories
 
I used Blackstone for years at the shop for aircraft engines but it is best used to see trends over the life of the engine. I think you are spot on with doing early. I think I will stick with 18 months regardless of mileage. The book says do the fuel filters at 18 months in the fuel section. Then in the oil section it mentions to always do the oil filter when doing the fuel filter but then just lists mileage tables with no mention of 18 months. I think it was an oversight.
Do you use the Shell Rotella 10/40 4T oil?
We used it exclusively in the Cummins on my boat. I had two of them and each held 24 quarts. With two oil filters each, those services were quite spendy.
 
I have considered the oil testing services as our Cummins engine holds 48 quarts. Add on the oil filter and the two fuel filters - just the oil and filters adds up to $$$.
Taking care of fuel filter changes myself. But still paying for oil service as I haven’t wanted to get setup for dealing with 12 gallons of waste oil on each change. So I tend to push towards the upper end of the oil change interval. But almost all the miles are highway so should be easier on the engine.
 
Yeah, you've stumbled into this GREAT controversy! A sure "fight" will ensue...LOL

Funny thing, I just went through the thought process for our ISX, with only 7k in a year.

I can give you the BEST EXPERT'S INDUSTRY STANDARD, vs. "CUMMINS" aka "let's make money" approach.

The "experts" will take Oil Samples and enter that into their log-books; and trust me/them, that has paid off for warranty disputes! Does every coach owner do that, or want to? No...but we "should" if we truly wanted the "perfect answer".

So, these whole Manual references are kind of frustrating, in a way. And, sometimes, Cummins will actually CHANGE them along the years and not even tell us. Ask me how I found out...and they don't keep a history either.

So, bottom line is, DON'T WORRY AT ALL in terms of your engine; our measly usage won't put a bit of lubrication stress on them, no matter whether we change oil every year, 10k, or whatever. Even a huge and heavy 60,000 pound coach pulling a stacker is a cakewalk for a 605HP X15. I realize you have the 450, but still...it's not pulling heavy loads like a trucker, and most sources I've spoken with agree that you can easily push out to the longest period between oil changes.
 
2018 Dutch Star 450 ISL
At first, I asked many and received inconsistent answers.

I change every 10,000
🤞🤞🤞$400-$500/change

One shop charged $460. The next time $1100. He would not come down and had already done the work. I showed him the previous receipt, it made no difference. I never returned
 
I change my oil and all filters every 10K miles. I bought my coach new in Sept of 2021 and did an oil change last year at Freightliner. Since it was its first oil change I didn't want to wait. The price was $1200 for everything.

HH
 
In my opinion for a vehicle with minimal use, it is important to follow a calendar rather than miles. Oxidative stress and moisture is more of a factor than anything else.
That said we change oil and filters based on the calendar recommendations by Cummins and Newmar.
This is especially important if you store your vehicle outside.
 
Just an FYI; the Pratt & Whitney F110-PW-220 jet engine in the F-16 does not have an oil change requirement. We just cleaned filters.
 
Mine's a 2007. I've changed it every other year and that's only almost 5,000 miles. 8.9 400 isl.

You may have a warranty on your cummins though. When I had my dually 6.7 cummins there was an oil change schedule in the manual and if I didn't follow it and keep proof (receipts) they could void my warranty. For this reason I always got it changed at the dealership at the recommended intervals which were much sooner than it needed.
 
I think 10k is a good number. I live in a very dry climate, if I lived in Michigan and started it up alot in the winter I might consider 7500
In the automotive dealership industry, even with manufacturers intervals of 7500 miles most dealers would say every 3000 miles is “cheap insurance”. Why? To get you in more often so that they had n opportunity to upsell you services and see new model cars you might like to upgrade too. This practice was bad for the environment and led to the service maintenance computer we all have now, where the intervals are calculated taking operating loads in to account.

Oil tests are interesting to me because if you get your oil tested and it’s less than 100% you now have somewhat of an obligation to stop driving and get it in for warranty service, failing to act expeditiously may lead to a why did you keep driving it with an issue. Also for all of you that have tested a late model engine have you had any bad findings? I’m curious
 
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Both FL and Spartan recommended mileage/calender. FL I believe was 12,000/12 months while Spartan is 15000/12 months and have been following Spartan recommendation.
 
Hello,

BGMAC - that is true about the oil in the F110 blower in your F-16. The P&W TF33 in my B-52 also doesn't get oil changes. But both of these engines are protected by the periodic taking of "SOAP" samples - the USAF Spectrometric Oil Analysis Program. If an oddball wear metal pops high, that engine comes off the wing and is soon on a truck headed to Tinker AFB, OK.

I have used Blackstone for oil analysis and I like their reports. They analyze for wear metals, moisture content, coolant contamination, fuel contamination and Total Base Number - how much of the detergents and cleansers, etc. remain in the additive package. They then tell you how these numbers stack up against similar engines of a similar mileage. I use full synthetic Shell Rotella T6 diesel engine oil in most of my engines (gasoline, too) because of its high amounts of "ZDDP" - zinc dialkydithiophosphate.

Do I do the analysis at every oil change? No. But they provide an excellent report when I do.

Rick
 
The skinny on Zinc

 
That is utterly ridiculous. Have you EVER seen anything in your owners manual where it says "beware of how much zinc is in your oil"? No.
Just use whatever oil is specified in the owners manual and there is nothing to worry about.
That clown is answering a question that was never asked. Looking for a solution for a non-existent problem
 
That is utterly ridiculous. Have you EVER seen anything in your owners manual where it says "beware of how much zinc is in your oil"? No.
Just use whatever oil is specified in the owners manual and there is nothing to worry about.
That clown is answering a question that was never asked. Looking for a solution for a non-existent problem
Thanks Dog, now I have to watch the video…..
 
That is utterly ridiculous. Have you EVER seen anything in your owners manual where it says "beware of how much zinc is in your oil"? No.
Just use whatever oil is specified in the owners manual and there is nothing to worry about.
That clown is answering a question that was never asked. Looking for a solution for a non-existent problem
Not going to watch again! As I recall the jest of the video is don't use additives, because they change that delicate balance!!!
 
I have an ISX12 in on a Spartan K3 chassis. Cummins documentation says that if the ISX12 is installed in a MH, that the oil needs to be changed every 6 MONTHS. I confirm this with Cummins via email. I did that once and now change it yearly based on 10K miles/year.

As far as the setup to change your own oil, it’s not that bad. When I still had a S&B, I change my own oil. I had the oil plug replaced (during oil change at Speedco) with a valve and when changing the oil, I would air up the coach to maximum height. I believe I could get a 5 gallon bucket under the coach, but I opted for a 3 gallon bucket. I would open the valve, fill the bucket, and then close the valve. I would then pour the 3 gallon bucket of oil into 5 gallons buckets. I would put the lid on the buckets and then take them to the landfill which had oil recycling tanks. It was 5 miles away.

Yes it’s more work to change it yourself, but I prefer doing things myself. I know it is done right, oil filter changed, etc.

Also being under the coach it gives me the opportunity to check things out for any issues that may exist.
 
Freightliner recommended 1-2-3 in their Fireside Chat literature. 1 being the annual oil and filter change, 2 being the engine air filter, 3 being the desiccant cartridge, etc...

I saw the change to 18 months. The problem is...I am just hitting retirement. We want to travel sometime spring/summer to Fall everyyear, while we can. I don't want to be doing an oil service during our trips. I'll keep on the annual service as a preflight for our annual trip, at least until we quit traveling a lot.
 
Here is some information on high levels of zinc and modern engines.

 

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