Shell Rotella T4 15W40

Messages
33
Location
Upstate SC
I just reviewed the PDS for Rotella T4 15W40, and I noticed that Shell now lists this HDEO as a synthetic blend. To confirm this claim, I contacted Shell and received a response stating that the formulation for Rotella T4 15W40 was upgraded to a synthetic blend in January of this year (2021). Given the lack of industry standards or regulations defining requirements for synthetic blend oils, the percentage of synthetic base stock, probably Group III, is unknown.

I noticed that several 15W40 conventional HDEOs, including Mobil Delvac 1300 Super and some store brands, are now being marketed as synthetic blends. However, all the oil marketers are not disclosing the percentage of synthetic base stock. So, the question: do these upgraded HDEO formulations provide any real performance advantages over Group II base stock diesel oils?
 
Messages
400
Location
kansas
It is likely there were not actually reformulated recently and they have been blends for a decent amount of time. They will likely all perform the same to how they were before the marketing change.
 
Messages
17,061
Location
Upper Midwest
And yes they do have real performance advantages over Group II base stock diesel oils. A better base stock is always better, in this case it probably helps to increase the viscosity index.

But will you notice? Probably not, unless the better base stock results in meeting more difficult approvals or specifications which is likely not the case in this instance.
 

Strokenmerc

Site Donor 2021
Messages
195
Location
Va
According to the labels, the old T4 was conventional, T5 was semi-syn, and T6 was syn. Now that T4 is semi-syn, is T5 needed or does it justify the price difference?

Just thinking out loud...
 
Messages
1,618
Location
Muncie, Indiana
From what I could see, the current formulations are API SN compliant, the older ones SJ to SM (2016 pds from shell)
Nope, none of Shell's HDEOs are rated for gasoline usage anymore, they all exceed the phosphorous limits, some briefly said SN/CJ-4, but around the time of the CK-4 reformulation shell dropped the dual rating in order to comply with new API rules that HDEOs were no longer exempt from complying with spark iginition phosphorous limits if they were dual rated, now to be dual rated they have to be within the limits of both specifications for spark and compression iginition oils.
 
Messages
1,618
Location
Muncie, Indiana
1614443222650.jpg

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This is a bottle I have that was filled in Sep 2019 and it has no S-rating
 
Messages
5,379
Location
down in the park
but the pds dated 2018 has, and if you look at the newer one side by side the only difference is the removal of the rating. So the oil was already semi-syn in 2018
 
Messages
13,241
Location
ROCHESTER, NY
This is just me however, I believe that just about(key words-just about) every conventional oil today is containing or will eventually contain some level of synthetic oil(probably a GrpIII) in its blend just to meet the API or engine mfg standards/requirements for that oil/engine, from a 5W20 to a 15W40 and maybe even a 20W50???
 
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