Another oil question

[Brock]

https://quickserve.cummins.com/qs3/pubsy...10340.html

I've run mobil 5w30 up until recently but only stopped due to oil leaks and a aging engine. My c15 was running the same 5w30 and really liked it but once again...... oil leaks out of every possible orrfice. ... the damn thing had just been rebuilt but it didn't matter, the oil is so thin at higher temps that you'll develop leaKS.

If your adding gear lube then you are changing the viscosity of your fluid anyways, That 10w30 will become a 12w35 whixh not many can complain about I'd imagine.