Castrol Syntec 5w-40 (be kind)

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Mar 18, 2005
Greenwich, CT
In short, I read the bottle yesterday and the CS 5w-40 is made from US and imported components and is not to be sold outside of the Americas.

My CarQuest guys stock this specifically for the Lotus dealer down the street and don't keep it out front on the shelf.

So, is this a true synthetic? I'm really trying to assimilate as much as I can.

Be kind.

Also available at most autozones. I currently have it in my BMW, It is my normal practice to leave it in only 4-5,000 miles. Many believe it is not a true synthetic. I also would like to know.
I just posted a VOA of this oil and a reply with the VOA info from the BC Castrol 5w-40.
The VOAs are close, both showing a large dose of Magnesium.

The current Castrol SDS dated 12/10/2004 says:
Castrol Syntec Synthetic Motor Oil
Synthetic hydrocarbons may contain one or
more of the following: [CASRN 68037-01-4,
64742-54-7, 68649-12-7, 64741-88-4, 92062-09-


5w-40 viscosity range at 100C 12.5 to 16.3

From another thread on the BC 5w-40:
Apparently it uses a blend of 68037-01-4 PAO along with the Shell XHVI 5.2 basestock . Now the percentages are unknown to me but those two basestocks are what the Shell Helix Ultra uses and it ain't no slouch

SLX/GC 0w-30 vs Syntec 5w-40 from Belgium
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