Rotella T4 15W40 + T6 5W40 = "T5 10W40"?

[SZR48207]

I have some odds and ends of these oils sitting around and thought about mixing them up in a roughly 50/50 mix.

The T6 5W40 is known to shear really quick in my bike, whereas the T4 15W40 remains quite stable for a reasonable OCI.

I know these can mix no problem, but would the resulting viscosity be 10W40?

 

[PaulManDude]

Lol I literally just started a thread about the same thing in autos a few seconds ago. I think the 15 weight stays 15 and doesnt get “watered down” to 10. At operating temp I believe it will stay a 40 weight. Not sure why syn would sheer down quicker

 

[beanoil]

The Widman viscosity calculator is your friend.
Hit the Shell site for PDS sheets with viscosity specs, plug them into the calculator, and see where you will actually wind up.
Calculator

 

[SZR48207]

Originally Posted By: beanoil
The Widman viscosity calculator is your friend.
Hit the Shell site for PDS sheets with viscosity specs, plug them into the calculator, and see where you will actually wind up.
Calculator


Very handy tool! The resulting cST @ 100C would be 14.52 so still a 40wt

 

[Papa Bear]

Are you looking for a JASO MA/MB (shared sump) mix??

 

[Overfill]

This makes a key assumption to me though. The main one being: does the mixing calculation apply for multigrade oils, or just monogrades? Dunno. The mixture looks good, but a good question is: what is your personal minimum riding temperature?

 

[CleverUserName]

Originally Posted By: Brian553

This makes a key assumption to me though. The main one being: does the mixing calculation apply for multigrade oils, or just monogrades? Dunno. The mixture looks good, but a good question is: what is your personal minimum riding temperature?


I just did an experiment with mixing multigrades oils of the same formulation, and I can say that the Widman Calculator is very close to what viscosity was measured @ 40c & 100c by OAI.

https://www.bobistheoilguy.com/forums/ub...tra#Post4688436