Which is better in performance tris or quad mesh

Hello

I just curious is openbve renderer work best in quad mesh or tris? 

Is there any significant between an addon use tris or quad mesh in term of performance for cpu or gpu?

Everything gets decomposited into tris when a model is loaded, so it makes no real odds.
Tris may be slightly faster to load, but unless it's an insane size model you're unlikely to notice really.

Internally, *every* graphics card will be working in tris, and indeed GL3.2 forward compatible profiles have deprecated quads entirely.