Originally Posted by mechjames
Rotella 5w40 or 15w40
This👆.. don't pigeon hole yourself into a single grade. If you're thinking you need a thicker oil for some reason, go with the 15/40... otherwise a 5w40 will work just as well as a 10w40. Heck, even the 15/40 will be fine depending on what the engine originally calls for.
Btw, Valvoline, NAPA, Castrol, QSAD are all fine 10w40's.