Conventional oil verses semi-synthetic

[rsmky]

It is my understanding that in order to achive the new API certification, 10W30 oils have a spike of synthetic oil.

Take Valvoline, is the 10W30 All-Climate the same formulation as the Dura-Blend 10W30?

Do anyone know for sure? Why buy the more expensive semi-syntheic when the conventional oil will do?

 

[Papa Bear]

Exactly !! ....

 

[Drivebelt]

SM 10W-30's can be made with only Group II's.

5W-30's require at least 50-60% Group II+ be added to the Group II (according to my research) to meet SM spec's, which puts the VI of the base oils in the 108-115 range. This is equivalent to a synthetic blend.

If a 5W-30 was blended from only a Group II+ (some may be) with a VI as high as 115, it would be the equivalent to a 50/50 blend of Group II and synthetic Group III.

Group II VI =100
Group III VI = 128
50/50 blend VI = 114

So the average 5W-30 conventional is equivalent to a synthetic blend, same for 5W-20's. Not the case for 10W-30's.

 

[Merkava_4]

I buy the Valvoline Blend at Wal*Mart because I get such a good deal on it there. I couldn't afford the stuff if I had to buy it at AutoZone.