Supertech 25w-40 or Rotella 15-40?

[monster1]

I've been running 15w-40 in my VP 4.3gxi for a few years now. I do one oil change a year as my yearly hours remain low. I noticed Wal-Mart is carrying supertech 25w-40 now which I assume is just rebadged Quicksilver. Should I continue with 15w-40 or switch? I'm running 15w-40 dino currently, but thought if anything, going to Rotella T6 full synthetic. What say you?

 

[bullwinkle]

T6 has been shown to be somewhat shear prone, and in extended high RPM marine use, that would be a bad thing. I've used Delvac 1300 in the 350 Mag Mercruiser for a few years now, since it carries a CF-2 rating (or at least "recommended for use"), I don't know anything about the ST 25W40-not sure if that would be Warren or not.

 

[blufeb95]

Originally Posted by bullwinkle

T6 has been shown to be somewhat shear prone, and in extended high RPM marine use, that would be a bad thing. I've used Delvac 1300 in the 350 Mag Mercruiser for a few years now, since it carries a CF-2 rating (or at least "recommended for use"), I don't know anything about the ST 25W40-not sure if that would be Warren or not.

The FC-W cert says it's made by Warren

 

[blufeb95]

Someone posted a VOA of SuperTech 25w40 about a year ago VOA - SuperTech 25W40 SynBlend Marine Oil

 

[monster1]

Originally Posted by bullwinkle

T6 has been shown to be somewhat shear prone, and in extended high RPM marine use, that would be a bad thing. I've used Delvac 1300 in the 350 Mag Mercruiser for a few years now, since it carries a CF-2 rating (or at least "recommended for use"), I don't know anything about the ST 25W40-not sure if that would be Warren or not.

Not sure why shear resistant oil is a bad thing. I thought thats one reason why many run HDEO in their marine engines?

 

[monster1]

Originally Posted by blufeb95

Someone posted a VOA of SuperTech 25w40 about a year ago VOA - SuperTech 25W40 SynBlend Marine Oil

Thanks. I think I'll stick with the 15w-40 unless someone tells me otherwise.