GTA4 DXVK (stutter and low performance fix for GTA IV and EFLC)

This is probably the best mod you are going to use to fix gta iv and SOLVE optimization problems, enb mods and reshade compatible!

Lamborghini LP570-4 Super Trofeo

Go ahead and have fun with this breathtaking car mod.

DXVK 2.5.3 and Shader Cache

DXVK is an API wrapper that translates DirectX calls to Vulkan. In layman's terms, it directs older, slower APIs into a newer, faster, and more efficient path thus helping with compatibility and performance. In the case of GTA IV, it solves many performance issues such as stuttering by alleviating CPU bottlenecks caused by DirectX 9.

GTA IV for low-end PC

This is some files that you could change to improve the FPS in the GTA IV...

ENBLITE

Small enb with minimal impact on performance:-Work on GTA IV 1.0.8.0 & EFLC-No framerates kill-No bug-No modification on vanilla game-Use the original post processing and all vanilla textures and content-Easy installation & uninstallation, past or delete all files

GTA IV Downgrader

This tool allows users to easily revert their Grand Theft Auto IV installation (versions 1.2.0.30 and up) from Steam or Rockstar Games Launcher to earlier versions such as 1.0.8.0, 1.0.7.0, or 1.0.4.0.