I've asked 2 nissan dealers on what oil they use on the xtrail:
1) Nissan Gallery- Caltex 15w40 diesel oil
2) Nissan Commonw- Valvoline turbo formula 15w40 API SJ/CF
Both claim these were supplied by Nissan Phil.
Guess the common factor is 15w40, mineral oil for either gas or diesel.

I've supplied Citgo 15w40 diesel oil and Conoco 10w40 Api SL, both were ok for warranty purposes. Manual actually prefers 10w30 but they don't use it.