Can you explain how this is a 5w30?

[KCJeep]

I'm looking at a couple of oils for my next OCI in my Jeep. In the past it has been my perception it seems to be happier on 5w30 than anything else I've tried thus far, despite the 4.0's reputation for liking heavier oils mine doesn't seem to. However since it will still be hot at next OCI I am looking at "heavier" 5w30's.

Anyway, I found one that interests me, but when I look at the specs I can't understand how this oil is labeled a 5w30.

Cst40C = 77
Cst100C = 12
VI = 151
HTHS = 3.3
ASTM D4684 = 60,000 @ -30

Other than a VI that is high for a 10w30 (and rather low for a 5w30) I don't see how this oil can be sold/labeled as a 5w30??? Isn't it really a 10w30 with high VI? And with an HTHS of 3.3 it appears to be thicker than a lot of 10w30's.

?

 

[barlowc]

The Cst40C = 77 is what stands out to me. Here are some 5W-30 numbers for comparison that I'd pulled a couple years ago:

Viscosity @ 40*C, cSt
Valvoline SynPower = 59
Castrol Syntec = 58.2
Castrol Edge = 54.17
Quaker State Q Horsepower = 58.5
Pennzoil Ultra = 61.9
Mobil 1 = 64.8
Mobil 1 EP = 61
Amsoil = 60.7

 

[Quattro Pete]

Originally Posted By: KCJeep

ASTM D4684 = 60,000 @ -30


The low temp pumping viscosity figure is certainly indicative of a 10w-XX oil. The test for 5w-XX oil is 60,000 @ -35C.

 

[A_Harman]

I think it's a 10w30, based solely on the cold pumpability test temperature of -30C. 0W's are tested at -40C. 5W's are tested at -35C. And the cold pumping viscosity that is quoted is right at the high limit of 60,000 cP, so I wonder if that is actually a result of testing, or one of those "Yeah-it-meets-the-spec" TDS's. Is this a Castrol oil?

For a 10w30, the HTHS is disappointing. The only reason for the existence of the 10w30 grade is to make a 30-weight that meets ACEA A3/B3/B4 specs, which require an HTHS of 3.5 minimum.

 

[KCJeep]

Okay thanks all I'm not crazy then. Yes its Castrol, the High Mileage 5w30 to be exact, I rounded the viscosity by a tenth or two so as not to tip it off too early.

So how can they sell this as a 5w30? There isn't some kind of requirement that has to be met to label it as such?

By the way the Castrol HM 10w30 does have the HTHS of 3.5 you mentioned A_Harman.

 

[Gene K]

100C - 11.99
40C - 77.2
VI - 151

Those all match and they are all different from the 10W30.

It appears to me that you simply have a typo. ASTM D4684 should list the temp at -35C on the 5W20 and 5W30. Instead it list the temp at -30C all the way across on the data sheet. 60,000 is the standard not the actual results achieved on the test. Castrol doesnt release that info.