What is the better synthetic diesel oil?

[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.

 

[CharBaby]

I don't think that a 5W40 would offer less protection at WOT than a 15W40. They're both a 40 grade when )))HOT(((.
The 5W or 15W is your (((COLD))) engine start-up grade in which(the 5W) may not be as beneficial or necessary in CA as it would be in NY. Or the same can be said for southern CA compared to northern CA.

 

[cptbarkey]

Any 15w40 HDEO from Supertech to HPL will do. Run 5W40 if you like for extended OCI.

 

[dnewton3]

The 15w-40 choices are perhaps a tad less likely to shear than the T6. Not because of the brand, but because of a 15-40w versus a 5w-40, and so the 15w has less VIIs. That would be true of any brand you'd compare/contrast, presuming similar base stock(s) are present.

You have zero need for a 5w rated diesel oil in CA.

 

[Pablo]

You have zero need for a 5w rated diesel oil in CA.

Well except any of the mountains. I snow camped as a Boy Scout, -2°F, San Jacinto, CA ca 1970 or so.

 

[facility1]

Schaeffers 9000 5w-40 would be my first choice,, and if cost a concern Chevron delo xsp 5w-40,,the amount of protection is debatable if to run 15w-40 especially at 10k change intervals

 

[fantastic]

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.

Any of those options mentioned will be great options. while I've run plenty of T6, Mobile has been way more competitive cost wise than the rest of them if using a rebate. Delo might be cheaper retail but you'd have to check first. I ran almost 10k on T6 on the Ford but it's use of oil as a hydraulic for the injectors can shear the oil a bit. The oil is mostly quite robust now though. It ended at 12.1 visc with a bit less than 3% fuel. A 15w-40 might fair a little better ending visc depending on fuel. The SN rating should not worry you if you know what you're looking for. Most 15w-40's don't have anything too low out of the ordinary but you will come across some like the Mobil 1300 that has much lower additives in it.

https://bobistheoilguy.com/forums/t...hell-rotella-t6-5w-40-uoa-9-443-miles.374967/

Here's the diesel info sheet

https://bobistheoilguy.com/forums/threads/voa-diesel-oil-database.362789/#post-6312439

 

[RateNate]

So either Mobil Delvac 15w40 syn or Rotella T6 15w40 syn is the choice then, would there be a better choice between the two? Weather here in NorCal can go down sub 30F sometimes but that's it.

 

[facility1]

rotella t6 would be a choice,,rember to compair CCS test for cold pumpability to a 5w vs 15 w

 

[Oro_O]

So either Mobil Delvac 15w40 syn or Rotella T6 15w40 syn is the choice then, would there be a better choice between the two? Weather here in NorCal can go down sub 30F sometimes but that's it.

Delo XSP 15w-40 is also good an in the same class a those. Also widely available and a rebate on right now. $7/gallon rebate w/3 gallon purchase.

https://www.chevronpromotions.com/Claim?promoId=1573

(I bought some Delo yeterday so it was fresh in my mind!)

Between Delo, Delvac, and Rotella in the same full-syn 15w-40, you won’t see a difference in performance.

 

[Bighorn2500]

Of the three full syn. 15w40's you mentioned which are all good oils, I'd go by the best priced off the shelf when needed.

You really can't go wrong with any of those choices.

 

[Foxtrot08]

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.

 

[OLEJOE]

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.

 

[dlundblad]

So either Mobil Delvac 15w40 syn or Rotella T6 15w40 syn is the choice then, would there be a better choice between the two? Weather here in NorCal can go down sub 30F sometimes but that's it.

Holy ****! There’s another thread going that would have one think Rotella is gutter water.

 

[tnt_motorsports]

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.

IMO, pick your favorite brand of HDEO in 15w40. I run Mystik JT8 in my 6.7L and have run both Mobil ESP 5w40 and Delvac 1300 15w40. FWIW I don't think you need a synthetic because most HDEO's are blend now not straight conventional...

With your 5.9L I wouldn't worry too much about the effects of Biodiesel on the oil and OCI. I'd be more concerned with fuel filtration. Biodiesel is a really good cleaner, so keep an eye on filters.

Just my $0.02

 

[SureshR]

What he said. India has been using at least 10% blended biodiesel for a while now. Change your fuel filter well before the normal interval. As for the soot, pick an oil that has high detergent - which most HDEO have - and also clean out eg your PCV valve / oil separator and EGR every 30-40k miles or so.

Valvoline Premium Blue One 15w40 SP/CK4 is also an interesting oil to look at.

 

[RateNate]

What he said. India has been using at least 10% blended biodiesel for a while now. Change your fuel filter well before the normal interval. As for the soot, pick an oil that has high detergent - which most HDEO have - and also clean out eg your PCV valve / oil separator and EGR every 30-40k miles or so.

Valvoline Premium Blue One 15w40 SP/CK4 is also an interesting oil to look at.

I have pushed the filters to 10k on oil and fuel but it sounds like the fuel needs to be more often? Would draining the water out be fine or is the filter needed to be cleared instead?

 

[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.

yea its 15-20 bio diesel down the street

 

[SureshR]

I have pushed the filters to 10k on oil and fuel but it sounds like the fuel needs to be more often? Would draining the water out be fine or is the filter needed to be cleared instead?

If your fuel filter is a cartridge type then change it, else drain the water and clean it somewhat earlier than your usual maintenance interval suggests.

 

[RateNate]

If your fuel filter is a cartridge type then change it, else drain the water and clean it somewhat earlier than your usual maintenance interval suggests.

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