Maxlife Semisynthetic 10-40 No Longer A3 Oil?

[KevinV]

I've used Maxlife 10-40 (Semi-synthetic) for over 7 yrs (and 200000). During this time it had an A3 designation but now Valvoline doesn't assigned it an A3 rating since it's an SN rated oil. I called Valvoline and the rep saif he didn't think the formula had been changed. Does anyone know if going to the SN designation would reduce the heat and stress rating (the A3 higher rating) or would it be just a change in the additive package ?

 

[KevinV]

To reword this question, if an oil becomes SN rated why would it (like maxlife SB 10-40) not have A3 designation when it had A3 designation as SM ?

 

[vinu_neuro]

I think there are some mistakes in the Maxlife Blend and Syn datasheets. On the Blend sheet they make a blanket statement for all the grades that they're GF-5 when 10W-40 and 20W-50 obviously can't be. Same way for Maxlife Synthetic they say A3 and GF-5 when they are more than likely mutually exclusive.

 

[KevinV]

That is a good point- are they mutually exclusive ? Anyone out there ?

 

[CATERHAM]

Kevin the reason you're not getting much of a response is because 10W-40 is an obsolete automotive grade.
It has been replaced by 5W-40 if not 0W-40 for all application that I know of.