Question about GC vs M1 15w-50

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1,116
Location
Huntsville, AL
One of the specs that I look for in an oil is that it meets not only the A3/B3, but also the B4 which is a tougher diesel spec than B3. While looking at a bottle of M1 15w-50 I noticed it meets the A3/B3 spec but did not list the B4. How can a thick oil like this not hold up to the B4 spec when a thin oil like GC 0w-30 can? Even if the M1 has alot of polymer VI's, would it shear to a weight less than GC? I wouldn't think so, but I guess it would. So what am I missing here?
 
Messages
9,448
Location
USA
Could also be that M1 did not test it for cert. for this rateing? You have to figure that they already have Delvac 1330,1300 and Delvac-1 wich are all diesel oils! THey may not want to compete with them selfs in the diesel market.
 
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