Cannot get 60 fps

Solution
More stuffs, to think about:
1060 should be enough for GTA V 1080p.
I7 2600 should be good for GTA V.
18GB RAM? It is very possible that you do not run the RAM on dual channel mode, you are losing about 5% performance by not having dual channel. GTA V gain advantage over faster RAM. I dunno how much the impact is on your system.
I forgot to mention nVidia ShadowPlay, it could cause stutters/frame drops for GTA V, you might wanna turn it off completely.

FIrst, I hope you did not fill mods on the game to the brimps

Have you checked in nVidia control panel that the 1060 is already running on performance mode and not energy saving or anything else?
Have you checked the similar settings but for the cpu in windows control panel?
How is your RAM capacity?
Can you check the background running app?
Monitor also the temps on your proc and gpu.
 
My PC specs are core i7 2600 with a Strix 1060 6gb. My power supply is 750 watt. And I have a 500 GB SSD. The resolution I run the game at is 1920x1080. With 18 GB of RAM. I do not use mods

 
More stuffs, to think about:
1060 should be enough for GTA V 1080p.
I7 2600 should be good for GTA V.
18GB RAM? It is very possible that you do not run the RAM on dual channel mode, you are losing about 5% performance by not having dual channel. GTA V gain advantage over faster RAM. I dunno how much the impact is on your system.
I forgot to mention nVidia ShadowPlay, it could cause stutters/frame drops for GTA V, you might wanna turn it off completely.

 
Solution