Not familiar with Motul so I'll let someone else comment about it.

Royal Purple 5w30 is for gas engines only. I think your trooper is a diesel. For diesel RP recommends its 15w40 you can also use their 10w40 or 20w50. Just use the viscosity your manual recommends.

Heres a link to their specs:

http://www.royalpurple.com/motor-oil-pp.html