What is the better synthetic diesel oil?

[tnt_motorsports]

Thats no fun, so 5k-7k intervals now?

I'd say for a few changes probably, but longer term you should be able to go back to a longer interval. Biodiesel is a good cleaner in the diesel fuel system. The cleaning action is what will cause the filter issues, not really the overall use of biodiesel.

Just my $0.02

 

[Brons2]

Delvac Extreme 15-40. Ran that in my 18’ 6.7. If I could put 15-40 in my 22’ model, that’s what I would run. Truck ran quieter and smoother. Call bs if you like. You weren’t here.

So the '22 6.7 does not allow 15w40 per the manual? I wasn't aware of this until now. What do they call for, the new high fuel economy 10w30 diesel oil spec?

 

[twX]

The issue with biodiesel is that it oxidizes easily in the presence of ZDDP. One study that did a 4-ball wear test with diluted oil found a small increase in wear with 1% aged biodiesel in the oil, and a doubling of wear at 5% dilution. Regular diesel actually reduced wear slightly even at 5% dilution.

If the fuel you're using only has ~10% biodiesel, the amount of biodiesel in your oil should always be
The ACEA and MB 229.5x oil standards have engine tests to measure an oil's performance with biodiesel dilution, whereas API CK-4 doesn't seem to have a biodiesel test. MB 229.52 has the most stringent biodiesel tests, but is only available in grades up to 5W.

 

[OLEJOE]

So the '22 6.7 does not allow 15w40 per the manual? I wasn't aware of this until now. What do they call for, the new high fuel economy 10w30 diesel oil spec?

Yes. In temps above 0 10-30 and below 0 5-40 but 5-40 is acceptable year round so that’s what I run. Would like to have a synthetic 10-40 to be honest.

 

[tarbe]

Yes. In temps above 0 10-30 and below 0 5-40 but 5-40 is acceptable year round so that’s what I run. Would like to have a synthetic 10-40 to be honest.

Seems like in LA you could use a good synthetic 15-40 and have your cake and eat it too! Except for the possible warranty issue.

 

[4WD]

RateNate ! Are you there there there there (echo) …

 

[Redhawk454]

So the '22 6.7 does not allow 15w40 per the manual? I wasn't aware of this until now. What do they call for, the new high fuel economy 10w30 diesel oil spec?

The valve train on 2019 and newer 6.7 Cummins can’t support 15w-40, allegedly. There was a technical service bulletin about it

 

[tarbe]

The valve train on 2019 and newer 6.7 Cummins can’t support 15w-40, allegedly. There was a technical service bulletin about it

I have not read the TSB. Is it due to cold flow?

 

[Strumpan_]

Almost every machine here is running 100% biodiesel and no problems. Our normal diesel have been a blend for 10 years and no problem either, so just do your normal oci

 

[Redhawk454]

I have not read the TSB. Is it due to cold flow?

15w-40 causes deposits in the valve lash adjusters, which can lead to damage, allegedly.

 

[tarbe]

15w-40 causes deposits in the valve lash adjusters, which can lead to damage, allegedly.

Hmmm....sounds like quite a generalization?

ie, not all 15W-40 is created equal. Seems like they should be talking spec/certification?

Just thinking out loud....and speculating. I would like to understand the what and the why of this allegation against a historically normative viscosity range oil, irrespective of certs.

 

[53' Stude]

Whichever one I see on sale with rebate

 

[RateNate]

Running 10k oci on our 03 5.9L hpcr, and in California we recently switched our fuels everywhere to a biodiesel blend now, so that affects our fuel filters but not sure on the oil life.
15w40 is what I'd prefer and seeing some threads on the new SN rating should that be a worry?
I see the shell T6 15w40 full syn or the mobil delvac extreme 15w40 syn options at walmart and the Delo 400 XSP SAE 15W-40. Let me know what you would recommend, and we have run a 5w-40 in it before with mobil tdt but on WOT I'd want that extra protection.

I forgot to add…. Its 10K miles over 2 years….. so 5k miles per year. Does going with a full syn make this safer?

 

[RateNate]

Biodiesel does tend to ruin OCI, as the blow by tends to be more acidic than conventional diesel fuel blow by.

That being said, Soot from blow by is what kills diesel engine oils anyways. So your OCI will be set by your soot loading levels, if you’re doing oil analysis. Fuel dilution will be a secondary characteristic to look for in any analysis.

Bio diesel blends are everywhere. Do you know what percentage Bio you’re getting? Or just anywhere between 2% and 15%?

If you’re running 10% or more (up to B20) - I would really watch any oil analysis and set your drain intervals accordingly.

Both 15w40’s and 5w40’s - assuming all are full synthetics - will provide approximately equal protection. While DNewton did point out the VII aspect, 15w40’s resist fuel dilution significantly better than 5w40s as well.

Since you’re running a 5.9, a bit older, I would suspect a higher fuel dilution rate than say, a brand new 6.7. With that, I would also expect a higher soot load there too, simply from more blow by. I personally would probably just run a synthetic blend 15w40 and change it more often, instead of going down the full synthetic route. However, if you want to go full syn, any of them will provide more than adequate protection.

Running into negative weather, you’re going to have more fuel issues with CFPP then you’re going to have oil issues at -2f, assuming syn blend or full synthetics. Especially with heavy percentages of Bio diesel. Your CFPP / CFCP could be as high as 10f if you’re running B15 or greater. A lot of this depends significantly on the quality of biodiesel being used to blend. Soy based vs rendering based. Etc.

Either way, any of the oils will provide protection. Watch your soot loads and fuel dilution.

Should I run 10K miles over 2 years on an OCI or stick with a cheaper yearly 5K now instead?
We pushed out to 10K now with the Donaldson blue filter, and it has the Delvac 1300 so that has to go asap. The bio blend locally is 15% and I do go to costco sometimes as well which supposedly has better fuel quality control.

 

[Foxtrot08]

Should I run 10K miles over 2 years on an OCI or stick with a cheaper yearly 5K now instead?
We pushed out to 10K now with the Donaldson blue filter, and it has the Delvac 1300 so that has to go asap. The bio blend locally is 15% and I do go to costco sometimes as well which supposedly has better fuel quality control.

I will always recommend a 1 year OCI.

That’s me. Especially with 15% bio, that’s alot of bio.

 

[RateNate]

I will always recommend a 1 year OCI.

That’s me. Especially with 15% bio, that’s alot of bio.

Hmm in that case we may just stick with a yearly change of semi syn or standard 15w40 since no need for full syn at that point.

 

[Strumpan_]

I will always recommend a 1 year OCI.

That’s me. Especially with 15% bio, that’s alot of bio.

Here we run the same oci with 100% bio diesel, HVO100, no problems here.

 

[SubieRubyRoo]

it has the Delvac 1300 so that has to go asap.

What’s wrong with Delvac 1300? There’s literally hundreds of billions of miles on this oil, in much heavier usage than 1/2-1 ton pickups, and the Delvac performs spectacularly for the cost. Why do you feel it has to go ASAP?

 

[GR_CoB]

I've been pretty happy with Mobil Delvac 1 ESP, in 5W-40 flavor. It's more robust than the Mobil1 TDT 5W-40. Using it in almost everything, from 1.4L T-Jet Fiat to a 6.7L Cummins Ram. Plenty of high RPMs, and never any oil-related issues.

 

[RateNate]

What’s wrong with Delvac 1300? There’s literally hundreds of billions of miles on this oil, in much heavier usage than 1/2-1 ton pickups, and the Delvac performs spectacularly for the cost. Why do you feel it has to go ASAP?

2 years on the oil 10k miles