Rotella 15W40 according to the MSDS is: Highly refined mineral oils and additives.
950/990 Oil Recommendation
>= 0C (32F) 10W/50 Fully Synthetic
< 0C (32F) 5W/40 Synthetic (Rotella T6 meets this, actually -but your 15W/40 meets neither spec.)
690 Oil Recommendation
10W/60 Synthetic Engine Oil
Alternate: 10W/50 Fully Synthetic Engine Oil
Which is why if I were traveling the world I would want a bike that could tolerate a large spectrum of oils. And not just well enough to get by, but well enough to still have long oil change intervals.