Lag on high end pc

Hello, I am experience some lag on a very capable pc. I get around 20 fps or so at native res (1920x1080) and normal settings.
My specs are: Intel Core i7 3770K OC @ 4.4GHz Liquid cooled
Dual GTX 660Ti in SLI
16GB 1600 ram
ASrock z77 extreme4 mobo
I can play almost any other games at ultra very smoothly. I guess maybe it could be game optimization, or some other factor? Are there any fixes other than lowering the settings?

Thanks guys,

 

Forcing SLI rendering should help a lot. Have a look at this. Guide-Nvidia-SLI-rendering-for-BeamNG-Drive

 

Awesome, thanks!