I've had some time to try different settings... no matter what I try I can't get a consistent 60 FPS. Lowering resolution and detail doesn't make much of a difference - even 1080P and medium settings with my hardware will not be smooth, and anything lower than medium doesn't look too good.
I ended up locking (vSync) at 30 FPS, this allows me to run 3440x1440 at Ultra settings - looks very good but not as fluid as I would hope (60FPS is expected on the PC, at least for me). More or less XOne performance but at an UltraWide resolution (can't set the resolution on my XOne). I guess for those without an XOne, at least there's a choice.
It seems a powerful CPU is needed (i7 @ 4.0GHz is not enough), not so much the graphics card, for 60FPS.
EDIT: There was a very noticeable steering delay at 30FPS until I found this tip on another site.
"If you are using a nvidia card, use nvidia profile inspector to set 35 fps (Frame Rate Limiter v2) under Sync & Refresh/Frame Rate Limiter and activate 30 fps lock and vsync in the game. There won't be input lag anymore."