Originally Posted By: Redland1
Hi,all I'm a long time follower of BITOG,but never have created an account.I have a 2013 DRW Duramax which is used as a full time Hotshot hauler,hauling loads of up to 36 GCVWR.I purchased the truck with 10 miles and have always changed the oil per DIC,which came out to something like 7k miles.The first oil change was Mobil 1,T6,T5,and then Rotella T from 15k to about 90k miles and then DELO 400LE from 90k to 143k all with AC Delco filters.My question is that I just deleted all the the emissions [censored] so that should supposedly extend the life of my oil from less fuel dilution and soot,so I am trying to see how far I could safely extend my drain interval with either DELO,Rotella T,or Mobil Delvac which I just filled the motor with? Sorry to be long winded.
Oh,and I know I could do oil sampling,but I really don't want that expense,and I think from all oil the samples here there should be an average safe oil drain interval without doing oil sampling.
First, Welcome
to the site as a member now.
Second, you can relax. The Dmax is one of the best wearing light-duty diesel engines out there; UOA macro data proves this.
Next, while not unheard of, it's kind of ironic that you want to save money by extending OCIs, but you're not willing to pay for the UOAs. Sir, that's a dichotomy if there ever was one. Simply put, you cannot have your cake and eat it too. There are four ways to know when to change oil:
1) arbitrary limit based on the odo; "
I change oil ever X,xxx miles ...."
2) IOLMs; typically very reliable and often conservative in their structure
3) Using UOAs as a toy; people look at them, and then promptly ignore the very data they paid for by not understanding the reasons why or why not to change oil
3) UOAs; using logical condemnation limits and data analysis to predict a safe and sane life-cycle for the lube (this is the most rare of all ...)
So by your own accord, you've chosen not to use UOAs. OK; fine.
That only leaves you with two options: #1 or #2.
I recommend you go with number 2.
You have no need to use a CI-4 lube; the ULSD fuel in North America now precludes any reason to use a CI-4. There simply isn't going to be enough acid formed that the higher TBN would make any difference whatsoever; again - UOA data shows us that. And, CJ-4 lubes actually have been proven by the big makers to reduce wear and increase cleaning properties; this is old news by now. Folks who tell you to use older API designations simply are stuck in the past and cannot let go and they don't understand WHY things changed.
If you still want to save a bit of money, then I suggest you shift your thinking to the choice of lube itself. Any qualified CJ-4 is going to do really well. Head right to W/M and get their ST CJ-4. For any sane OCI duration (as dictated by the IOLM) it will be a great job AND save you a bit of money. However, there are times when even brand names (like the big three; Delo, Delvac, Rotella) can be found on sale or rebate. The point is to pick the least expensive CJ-4 at the time of service and use it. Both VOA and UOA data show that house brand oils are every bit as capable as big brand names. So do your wallet a favor as save a little, because your engine is never going to know the difference. There is no need to be brand loyal here; be true to your wallet. For the IOLM distances (and even past that) any licensed API CJ-4 will do everything you need it to do, and still have plenty of safety margin left for that "peace of mind" and "cheap insurance" that some folks simply insist upon.
Also, read this; LOTS of data regarding OCIs and specific to the Dmax:
http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/