Delvac 1300 Super 15-40 vs Mobil 1 5-40 Cummins

[JStep]

Hey all!

Hope the new year is starting great for everyone!
I have another "oil preference" question. I have a 2005 Dodge Cummins. It is a daily driver but does not get driven much. Allot of short trips and allot of below operating temp driving, which I know is not good. I have been using Kendall Super D-XA Titanium. However I recently moved and it is no longer readily available. Soooo, here is the big question. I have narrowed things down to Delvac Super 1300 15-40 or Mobil 1 5-40 syn. The Delvac is about $13 a gallon whereas I can get the Mobil 1 Syn for $20/ gal. Since there is not much price difference (3 gallons per OC), would my engine benefit from the SYN 5-40 for the short trips? If I drove her hard like I should, I would not be asking this question. But I am thinking the 5-40 Syn may do better for this below operating temp driving. I do not do extended OCI's as more time passes than miles so don't like all the "gunk" sitting there a long time.

Thanks for the input and opinions@
James

 

[bullwinkle]

In FL, I don't think it would make much difference between dino 15W40 & 5W40 syn. I use 5W40 syn in my '06, but it has some difficulty starting in cold weather (weak CP3 high pressure pump), but 15W40 is recommended, & it's hard to find a better one than Delvac 1300. I try very hard to avoid the short trips/unloaded usage on mine, if I was in your situation I would change every 5K or less, & UOA for excessive fuel in the oil.

 

[JStep]

Thanks for the input Bullwinkle! Ya, I was on the fence about it. I try to avoid running the truck on the short trips as well. She gets a workout when I pull the boat around which is happening more often now that I live closer to the coast!

On a side note, have you tried replacing the FCA (Fuel Control Actuator) on your CP3? I recently thought I was losing an injector and did allot of research on the subject. I replaced the FCA (about $100 at Genos Garage or your local cummins supply). Truck has never run better. Takes 5 mins to change and allot cheaper than a new CP3 or injectors! There is also a Fuel Pressure Sensor on the fuel rail that could be the culprit. Cheaper to buy the whole fuel rail that comes with the sensor tho! Or you could do the 6.7 fuel rail upgrade from GDP (Glacier Diesel Products) also!

 

[BobFout]

Yep, Delvac, Delo or Rotella 15w40. Or if you want to support a FL business, Amalie oil with their Wolf's Head brand.

 

[CT8]

There is really no need for a 5W in fla. What gunk are you talking about? A vehicle is a tool drive it as needed.

 

[JStep]

CT8, thanks for the input. The "gunk" I'm talking about are the soot, acids and other contaminants that build up more quickly from my short nom-operating temp trips. I read allot here but don't know much about oil and how diesel byproducts affect oil. My assumption is that since I am not putting allot of miles on the truck, time should be considered for OCI's. If I'm wrong, please educate me. Would save me a few bucks. Thanks!

 

[beanoil]

For Florida's moderate temps, I don't see a need for 5w. Your short trips might build up some moisture, fuel, sludge, so a UOA can tell you where the sweet spot is. I'd be very tempted to stock up on the 10.00 a gallon NAPA house brand oil on sale and give it a run. Changing early if you need to won't hurt you with 30.00 worth of oil.

 

[edyvw]

Although in FL you do not need 5W, considering exploitation, I would go with 5W40.
75% of wear happens during cold starting, and 5W40 is probably mix of Group III and IV base stocks and has better ad pack. It will do better with all "gunk" then 15W40.
I would try either M1 or Shell T6.

 

[dnewton3]

JStep -
You have a daily driver that doesn't get driven much? Not even up to temps, etc?

Here are my recommendations ...

1) Presuming you're in FL, there is no need for a syn, especially an expensive PAO, unless your OCI plan is super-long extensions
2) You might consider using a 10w-30 HDEO rather than a 15w-40; it will come up to final grade perhaps a bit quicker, but since you're not very descriptive about the overall conditions, this is only a guess on my part
3) get some UOAs and compare/contrast those to others in similar use; try to understand just how bad (or not bad at all ...) your situation really is
4) consider getting rid of the diesel; you are using a HD truck like a car. Get a car or get a gasser 1/2 ton. You don't mention using the truck to haul or tow, and given that you don't get up to temps, you're probably way under-utilizing the rig you have. Get a 1/2 ton; they are very capable today and will likely fit your use better


The downside to your current use is that short trips which never reach operating temps can be a bit trying on the equipment, but until you test your wear rates you're just completely guessing ... The upside is that it is a Cummins (pre-DPF, etc) and probably will still last a LONG time, given your low accumulated mileage.

 

[CT8]

Originally Posted By: edyvw
Although in FL you do not need 5W, considering exploitation, I would go with 5W40.
75% of wear happens during cold starting, and 5W40 is probably mix of Group III and IV base stocks and has better ad pack. It will do better with all "gunk" then 15W40.
I would try either M1 or Shell T6.
It is not because of the 15w-40 in Fla temps that are the cause of more wear as the engine gets up to operating temps. 15w-40 is rated for approx 15*f starting temps. Any oil will get more contamination from short trip use .If short trip use is dome change the oil more often.

 

[dnewton3]

Shorter OCIs do not reduce wear rates.

To the contrary, it is actually the aging of the oil, developing the TBC barrier, that reduces wear rates.

Read my normalcy article and the SAE study referenced therein.

 

[Shannow]

Originally Posted By: dnewton3
Shorter OCIs do not reduce wear rates.

To the contrary, it is actually the aging of the oil, developing the TBC barrier, that reduces wear rates.

Read my normalcy article and the SAE study referenced therein.


Again, that's not what the SAE paper said...

 

[CarbonSteel]

Originally Posted By: Shannow
Originally Posted By: dnewton3
Shorter OCIs do not reduce wear rates. To the contrary, it is actually the aging of the oil, developing the TBC barrier, that reduces wear rates. Read my normalcy article and the SAE study referenced therein.
Again, that's not what the SAE paper said...
Shannow - can you elaborate on this?

 

[bullwinkle]

Originally Posted By: beanoil
For Florida's moderate temps, I don't see a need for 5w. Your short trips might build up some moisture, fuel, sludge, so a UOA can tell you where the sweet spot is. I'd be very tempted to stock up on the 10.00 a gallon NAPA house brand oil on sale and give it a run. Changing early if you need to won't hurt you with 30.00 worth of oil.
This is the route I would go too-follow the severe schedule interval, run the lowest cost name brand 15W40 HDEO you can find, with a decent filter. Use UOA to make sure you are getting the moisture burned off, try to go on a long run, preferably working it via towing or hauling, at least once a month. That's the only way to be sure, at least it won't take you 10 miles to get it fully warmed up like us northern guys in winter!

 

[Shannow]

Originally Posted By: 2015_PSD
Shannow - can you elaborate on this?


The paper takes used engine oil from a number of vehicles, with a number of miles in service, then they place the oil in a test machine that rotates a cam (Ford Zetech) against a shim. Shim was treated through radiation so that wear could be measured via tracer methods etc.

Oils were fresh, and used, up to 15,000 miles.

Procedure...New cam and "lifter" for each of a number of oils.
Put new oil in new assembly.
Run for 50 hours (too many variables in the "breakin" phase, discard result)
Run for another 50 hours, record the results.
Flush the machine, with solvent, and the test used oil, repeat a 50 hour test.
Repeat for as many used oil samples

Of the three test oils, during the first measured phase post breakin on new oil, one oil produced 0.09mg of wear, one produced 0.14mg, another produced 0.05mg of wear.

For the used oil tests, same cam and shim, the first oil produced virtualy zero wear from that point onwards. The second dropped to around 0.02mg for the 3,000, and 5,000 mile oil and virtually nil from that point onwards.

One of the oils that they tested, they flushed the machine after testing on used oil refilled with virgin, and ran the test. It produced more wear on fresh oil, but was still around 1/4 of the wear of new oil in new assembly.




The mechanism for this is really that when an oil is made, there's only one or a couple of chemical species. Call this "fresh" ZDDP.

In service, through heat (like contact areas on cams etc.), and oxidation, there are changes in the ZDDP, and it ends up with a sump full of "different" zinc bearing compounds, all of which react differently. (as an example, MoDTC forms MoS2 in the tribofilms (not this paper, but others...not a reason to dump MoS2 into an engine though, these are tiny scale things).

The authors, in their conclusion offer that as the explanation for their findings.

The problem that I have with the absolute assertion that frequent oil changes mean more wear is that given the conclusion of the paper, and that no oil change involves a total flush like the test machine, maybe 10% (or more) of the used oil is still in the engine...with all of the reactive species that they carry.

The paper doesn't demonstrate, nor infer that's not sufficient to keep the radical species functioning...I'm not saying that it is, not saying that it isn't but that increased (negligible) wear with the fresh oil on the used shim was with a solvent flushed change-over.

The assertion that viscosity doesn't matter IS presented in the paper, but the paper is on valvetrains, which everybody knows is largely additive dependent, not viscosity...not all of the engine parts are lubricated by tribofilms.

Has no inference on start-up wear, nor "all of the oil has drained to the sump, so the engine is dry, on tribofilms"...I've never pulled apart a dry engine yet.

Also, the "no wear" high mileage oils were in use in the taxis well beyond what would normally be condemn limits.

All had thickened out of grade (xW20) by 7,500 miles. By 15,000 miles, they were all 40 grades.

All had TBN/TAN crossover between 7,500 and 15,000 miles.

There's more to it than "used oil protects cams better".

(Actually, I DO take away that used oil would probably make a better first fill on a new engine however)

 

[Shannow]

Originally Posted By: bullwinkle
This is the route I would go too-follow the severe schedule interval, run the lowest cost name brand 15W40 HDEO you can find, with a decent filter. Use UOA to make sure you are getting the moisture burned off, try to go on a long run, preferably working it via towing or hauling, at least once a month. That's the only way to be sure, at least it won't take you 10 miles to get it fully warmed up like us northern guys in winter!


Problem with diesel is it's distillation curve...

You'll never get it hot enough to get it all out

 

[CT8]

Originally Posted By: dnewton3
Shorter OCIs do not reduce wear rates.

To the contrary, it is actually the aging of the oil, developing the TBC barrier, that reduces wear rates.

Read my normalcy article and the SAE study referenced therein.

With short trip use changing the oil sooner gets rid of the moisture fuel dilution etc.

 

[Shannow]

re the SAE study...there's a bunch of UOAs on the way through the process in the life of the taxi fleet.

One of the oils goes from no detectable Fe to 155 ppm at 5,000 miles, then declines to 32 at the end of the 15,000 miles.

If you did a UOA at the end of the 15,000 miles, would you say that the oil was fine (on Fe)...well what happened in the middle ?

Did it "wear" badly from 3,000 miles to 5,000 miles, and then start to bury the Fe in a sludge layer after TAN crossed TBN ?

 

[CarbonSteel]

Originally Posted By: Shannow
Originally Posted By: 2015_PSD
Shannow - can you elaborate on this?
The paper takes used engine oil [...]
Many thanks for your thoughts. It would indeed make sense for the residual oil from a prior OC to impact the numbers. I believe that Ed Hackett posted something recently that gave a clear example of how this condition can affect wear metal counts, so thanks to both for the information.

 

[Shannow]

Yep, Ed Hackett's analysis is the apparent "spike" in wear metals at the start of an OCI that "settle out" with time, explained through residual effects.

It's very valid.