Castrol GTX HM -vs- Maxlife

[Merkava_4]

Castrol GTX HM 10w30:

66.8 cSt @ 40C
12.1 cSt @ 100C

Valvoline Maxlife 10w30: (conventional)

70.4 cSt @ 40C
10.66 cSt @ 100C


Question: How is it possible for GTX HM to achieve a lower 40C number and yet even a higher 100C number than Maxlife?

 

[Ugly3]

Viscosity Improvers.

 

[Merkava_4]

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Viscosity Improvers.

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Would that mean that Castrol has a thinner base oil to start out with?

 

[TallPaul]

It would seem that the Maxlife has a thicker base oil and the Castrol has more VII. Between the two I would prefer the thicker base oil. You can always match the 100C viscosity of the Castrol by mixing 50/50 the Maxlife 10w30 with 10w40. But is 66.8 and 70.4 really all that different?

 

[Merkava_4]

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But is 66.8 and 70.4 really all that different?

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That's what I'm wondering.

 

[Merkava_4]

Bump!

Would there be less wear at start up with 66.8 cSt @ 40C as opposed to 70.4 ?

 

[Merkava_4]

Well since no one wants to answer the question, I'm going to assume that there won't be any difference.

 

[TallPaul]

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Well since no one wants to answer the question, I'm going to assume that there won't be any difference.

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That is a good assumption.

 

[Doc8404]

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Well since no one wants to answer the question, I'm going to assume that there won't be any difference.

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so which did you choose?