Originally Posted By: CATERHAM
Originally Posted By: Terra_Nova
Originally Posted By: Pablo
Originally Posted By: CATERHAM
To my way of thinking, unless a synthetic oil has a VI greater than 165 it's a poor value.
Unless that VI is achieved with low grade VII's and PPA's. To me, this is the weakness of using VI as a guide for choosing motor oils.
Is it reasonable to assume that in order for Toyota to get a 0W20 VI of 216, this very high VI was achieved primarily by mean of the heavy use of Viscosity Index Improver additives ?
So, if you had a Group 3 base stock, the additives would help drive the VI to such a high number of 216 ?
And I suppose with an Amsoil oil with a Group 4 base stock, the inherent nature of the Group already has a naturally high VI to begin with and may not degrade as quickly as an additive enhanced VI might.?
Could a Group 3 base stock with such a high VI, derived primarily ( I assume ) from additives sustain that VI spec over an extended drain interval in your view ?
Welcome your thoughts.
The following is a VOA of the current SN Toyota 0W-20:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2409059&page=3
It's a lengthy thread and makes reference links to a comparison with M1 0W-20.
The recommended OCI by Toyota USA for the Toyota 0W-20 is 10,000 miles and there are quite a few UOAs of the oil one can review.
Thanks !