Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 02-27-2009, 10:29 AM   #1
Junior Member
tabo35's Avatar
Join Date: Feb 2009
Location: Full Time Moving
Posts: 11
Looking for thoughts on the oil change intervals for large diesel engines. I have a 525 Cummins ISM engine, the manufactures recomendation is 18000 miles or one year. The sump on this engine is just under 50 us quarts. The milege driven is about 8000 miles per year. Any input would be great.

tabo35 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-27-2009, 11:55 AM   #2
Senior Member
GaryKD's Avatar
Newmar Owners Club
Join Date: Jul 2006
Location: Wellington, Florida
Posts: 13,599
Hi Ron,
Welcome to iRV2. For me there is no question about this. Obey the Cummins recommendation. For you it would be once per year. Bad stuff builds up in the oil. The once a year recommendation is to make sure all the contaminates are drained out of the engine instead of continuing to contaminate all the parts. If there is a time of storage or extended non-use, consider changing the oil just before this time.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
The Avatar Is Many Times Around The USA
Nobody Knows Your Coach Like Somebody Who Owns One Just Like Yours
GaryKD is offline   Reply With Quote
Old 02-27-2009, 12:31 PM   #3
Senior Member
RVThere's Avatar
Freightliner Owners Club
Join Date: Aug 2008
Location: Florida Keys
Posts: 2,618
Based on a suggestion from my brother-in-law who was responsible for diesel maintenance in the Navy for 25 years, I have gone the Oil Analyzers, Inc. route where you take a sample of oil at periodic intervals and send it in for lab analysis. The lab report then tells you when the impurities and viscosity of the oil is approaching a threshold where it needs to be changed. According to the bro-in-law, the Navy has been doing it this way for years with a tremendous cost savings.

Depending on your situation, you may be getting rid of perfectly good oil. Beside the economic benefit to you, there is also an environmental benefit of minimizing the use and disposal of lubricating oil.
Tom and Katharine
'07 Winnebago Tour 40TD, 400hp Cummins
'17 Winnebago View 24V, '02 R-Vision B+
RVing for 20 years & 200,000+ miles
RVThere is offline   Reply With Quote
Old 02-27-2009, 02:59 PM   #4
Senior Member
AFChap's Avatar
Winnebago Owners Club
Spartan Chassis
Join Date: Aug 2002
Location: ...hopefully on the road!
Posts: 5,093
My ISC recommended is 15k or 12 mo. I drive anywhere from 6k-9k per year. I have mine changed annually along with chassis lube, etc.
Paul (KE5LXU) ...was fulltimin', now parttimin'
2003 Winnebago Ultimate Advantage 40e
towing 2017 Jeep Grand Cherokee Limited
Blog at
AFChap is online now   Reply With Quote
Old 02-27-2009, 04:25 PM   #5
BigSkyBob's Avatar

Monaco Owners Club
Join Date: Feb 2008
Location: Western Montana on the Divide
Posts: 1,524
Annually unless I reach the required change due to mileage. I usually do about 7000 per year. Time is equally as important as mileage.
Bob Retired Army Traveling alone now, had to put Charlie the Beagle down :(.
2008 Camelot 40 PDQ 4 slides ISL400 towing a 2020 1500 GMC Sierra Denali 4x4 Crewcab
Western MT in summer, AZ, NV in winter
BigSkyBob is offline   Reply With Quote
Old 02-27-2009, 09:11 PM   #6
Senior Member
bdpreece's Avatar
Monaco Owners Club
Join Date: Mar 2000
Location: Yuma Arizona USA
Posts: 2,930
I have yet to reach the recommended mileage for changes so just change annually.
Brian, Loretta & Daisy (Golden Retriever)
2008 HR Endeavor 40 PDQ , ISL 400
2010 Dodge Ram 1500 Toad
bdpreece is offline   Reply With Quote
Old 02-28-2009, 01:46 AM   #7
Community Moderator
RV Wizard's Avatar

Country Coach Owners Club
Appalachian Campers
Gulf Streamers Club
Join Date: Mar 2000
Location: Chattanooga, Tn.
Posts: 12,061
Ron, welcome to We are glad to have you join us here.
I would recommend you do not exceed the maintenance schedule, especially if your engine is in warranty. And that you keep all records of service; document the date and mileage if you do your own changes. This will come into play of you ever have an issue that has to be warrantied by the manufacturer. Good luck and enjoy the website.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7
RV Wizard is offline   Reply With Quote
Old 02-28-2009, 03:58 AM   #8
Senior Member
footdoc's Avatar
Join Date: Jul 2006
Location: Mobile, Alabama
Posts: 1,002
Tom...I checked out that website and have a your year old oil report comes back that everything is ok for continued doesn't tell you when to recheck it again at $22.50 a pop, plus the hassle of getting a 3 oz your oil can be fine....until when??? How often do you retest and worry about it in between tests? And then get the dreaded report that it's been too long
2006 Mountain Aire 43 and 05 Honda Pilot
Air Force One..Real Whirlpool Fridge !
3 sugar gliders, long hair daschund and short hair wife for security
footdoc is offline   Reply With Quote
Old 03-02-2009, 03:53 AM   #9
Senior Member
Join Date: Apr 2003
Location: Oakton, Va
Posts: 1,160
When you have 50 quarts of oil to deal with I would consider an alternative such as an oil analysis. One thing I am concerned about is acid build up. This is water combing with the sulfur oxide to form sulfuric acid. I had one oil analysis done for a general check on my 5.9L diesel and found the company, Blackstone, to be most helpful. They answered my question and essentially educated me as to what the analysis meant and what it assured me of. Following the guidance that the analysis labs give may let you extend your interval. After a certain amount of testing and getting repeated results you will find your change interval and after that testing will not need to be done every year. BTW my 16 quarts get changed every year because it is just 16 quarts and because I do it myself. I also get a filter change at the same time.
Jim Walker
N Virginia
2014 Palazzo 33.2
Cummins 6.7 ISB, Allison 2100 6 Speed
J Walker is offline   Reply With Quote
Old 03-03-2009, 02:20 AM   #10
Senior Member
RVThere's Avatar
Freightliner Owners Club
Join Date: Aug 2008
Location: Florida Keys
Posts: 2,618
Getting the oil sample is not problem as I have a little hand pump with a long tube that goes right down the dipstick tube.

As with any scientific testing, the results you receive follow a normal progression. You don't get 'good oil' with one test and 'bad oil' with the next. You test every year and when the oil is at a point where it APPROACHES 'bad' (or out of the tolerance interval), you change it.

Why guess at something when you can make an educated decision based on fact?
Tom and Katharine
'07 Winnebago Tour 40TD, 400hp Cummins
'17 Winnebago View 24V, '02 R-Vision B+
RVing for 20 years & 200,000+ miles
RVThere is offline   Reply With Quote
Old 03-04-2009, 04:24 AM   #11
Senior Member
Join Date: Jul 2005
Location: Pahrump, NV
Posts: 329
We run over 8,000 mi/year on average. Per C ours is good for 1 year or 12 months. So we change it every year...small price to pay to protect the engine.

In addition, about 1/2 through the year we pull a sample (very eay with the pump and some plastic tubing) for a check. This is not to extend the interval but to see if there is any early indication of something going wrong...coolant, bearing, etc.
2011 Airstream Classic Limited
2011 GMC Sierra 2500HD Duramax/Allison
Techie is offline   Reply With Quote
Old 03-04-2009, 01:09 PM   #12
Senior Member
Join Date: Jul 2007
Posts: 156
Just as a point of reference - With fire apparatus we go with a 250 hr interval between changes.
2007 Georgetown 373 f53
2007 Colorado
2019 JL Wrangler
Nutmeg is offline   Reply With Quote
Old 03-10-2009, 09:53 PM   #13
Senior Member
motojavaphil's Avatar
Join Date: May 2007
Location: Rio Rancho, NM
Posts: 1,051
We change engine oil every year no matter the mileage although above 8G I'd do another change and have purchased a small air grease gun for chassis lube every 4-6 months due moisture or dirty conditions. I have too much motorcycle discipline to not just do it.
Phil & Carol & Ariel, Grey Lady
2016 Ram CTD 4X4
2009 Carriage Cameo F35SB3:dance
motojavaphil is offline   Reply With Quote
Old 03-10-2009, 10:19 PM   #14
Senior Member
RVDude's Avatar
Join Date: Sep 2006
Posts: 1,339
Cummins does have an extended change interval procedure for most of their engines. It involves different filters and perhaps other stuff depending on your engine. Cummins further specifically disapproves of oil testing as a means for extended intervals. Cummins also provides different specs for engines that are designed for and in use by commercial/industrial/fire and these uses all have differing interval specs. Search the Cummins site for details.

With the Cummins *facts* out of the way, my *opinion* is that RV usage - because of the typically lower miles - usually has time trumping miles. Change that stuff annually. Don't skimp. The filter too. Why play with the life blood of your $30,000+++ engine?????? Consider it a DIY ~$120 or a ~$200 insurance policy. And, as was also mentioned above, get it tested just to see what's going on inside that beast. Might be an early warning for you.

I do my ISM (10 gals or so) DIY using 3 5 gal pails under the un-jacked rig all sitting in a garage floor drip pan. Pull the plug and slide the pails over as they fill. Seldom even a splash. Then funnel them off into smaller resealable containers to shuttle to the recycle tank at the local auto parts. A very straightforward job. Spin off the filter(s) and replace. Rotella from WalMart and Fleetguard filters from Spartan (cheaper than from Cummins). Of course you can hit a SpeedCo for about $80 more than DIY. That's a pretty good deal too!
2007 and 7/8ths Newmar Essex 4502
RVDude is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
New low-Sulphur Diesel Fuel--Impact on older Diesel Engines Uncle Ben MH-General Discussions & Problems 7 01-01-2008 07:17 PM
New Cat Diesel Engines Sammie Winnebago Industries Owner's Forum 8 08-04-2006 12:00 PM
'07 new diesel engines journeylad Newmar Owner's Forum 6 07-01-2006 11:24 AM
Diesel oil-change to synthetic? PairoDocs Newmar Owner's Forum 7 08-06-2005 09:07 AM
Diesel Oil Change Question chasfm11 MH-General Discussions & Problems 11 01-05-2005 11:34 AM

All times are GMT -6. The time now is 04:56 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.