This is a mod that changes your (tire) smoke textures & quality. If the game before lagged with original SLRR smoke, this mod will lag - if you didn't had lag, it won't lag.
To install that mod, you need to extract the asphalt.tga to .../particles/textures/particle_clouds & you're done.
Preview of mod of course.
Archived external download: Download (external link)
Archived from VStanced • Textures • 2014-07-24