Originally Posted By: Burbanite
Originally Posted By: dnewton3
Burbanite -
While others will spout mythology and rhetoric, I offer real world data based upon thousands of UOAs and personal experience.
I can offer two substantial pieces of advise here:
This -
http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
And this -
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=3173384#Post3173384
I can say with complete confidence, and the full spectrum of both macro and micro data, that the Dmax won't give a hoot what's in the crankcase as long as it's a properly spec'd HDEO (in your case, CJ-4).
If you are not GREATLY extending your OCIs, then using syns is a total waste, especially in a Dmax. This is not my "opinion" but rather a solid conclusion based upon reams of data available for you and everyone to see. However, as I often say here at work, while I can explain something to you, I cannot understand it for you. If you allow emotion and bias to cloud your vision, then the truth will elude you.
There is absolutely nothing wrong with "wanting" to run syns; that is an emotional choice. But rational decisions point to there being no "need" to do so.
As you can see, I am preferential to dino 10w-30 HDEO. That is because I like to try "new" things and prove or disprove them. Clearly, I've been successful in showing thinner dino lubes do every bit as well as thicker syns, even during very hard use and extended drains. However, my actuall recommendation is not for any particular brand/grade, because the data shows that it simply does not matter. While you pay $10/qrt, other are paying $10/gallon, and yet they get the exact same results. That is a 4x factor you are paying for, and getting absolutely nothing in return for your money! If you are dilligent, you often find HDEO on sale/rebate for well less than $10/gallon (Peak was $8/gallon off the shelf at AAP this past summer and Delvac 1300 was $7/gallon early this year with rebate). You are at the very high end of costs. You could save a TON of money, and still get the same statistical results. Your engine won't know the difference, but your wallet surely will!
I totally understand what you are saying but I'm still partial to using Synthetic oil, just not such an expensive one which is, as you mentioned "A waste of money" for the amount of mileage I put on this vehicle every year.
I figure I can still use a full Synthetic and cut my Oil bill by more than 50% of what I'm paying now and since I only change my oil once a year, I can live with the cost.
I was thinking of switching to either Delo 400LE Synthetic, Shell Rotella T6 or Mobil 1 TDT. All these oils are a 5W-40(CJ-4) and cost about $20.00 per gallon which is a price I can live with.
Delo also makes a CJ-4 5W-30 Synthetic which they say is made for Class 8 vehicles but I'm sure it would work in a Dmax. My only reluctance is switching to a 5W-40 instead of using the recommended 15W-40. It doesn't get that cold here in the winter so I was wondering how the 5W-40 would work on start up in the hotter summer months?
I'm kind of leaning towards the Delo as I've always had good luck with their products but I'm sure the other two I listed are good products as well. I appreciate your input on my so called dilemma(Along with the other peoples posts)as I have great respect when it comes to your input on engine oil related issues.
Op
Your climate isn't brutal so that makes start up viscosity less important(5w vs 15w) so that variable is less important and you can use whatever grade you're comfortable with as long as it meets your spec(cj-4).
You're gaining nothing using a synthetic at your mileage interval but it's your money,spend it how you wish.
I suggest devlac elite 222 0w-30. I believe it meets cj-4,it's synthetic and is a great oil.
Dnewton has extensive data on the duramax so his recommendation is based on acquired data.
Using the devlac I suggested will lower oil temps,warm up quicker,use less fuel and provide fantastic protection on those uphill climbs.
If you're going to stay with a syn I suggest doubling the interval and at least get some value from it,remember synthetics were made for extended intervals and if you read bitog a home page articles you'll learn that extending oil change intervals actually lessen wear rates per mile.