I'll bet teh Shell Rotella Team will recommend T3 or T6 which are both on the Allison list for shared sump duty. Allison also lists Rimula R4-L, but don't know what the availability is ...
Shell is well represented in the Allison list
Me, I'd run T6 and call it a day
Shell is well represented in the Allison list
Me, I'd run T6 and call it a day
