Vehicles stop instantly when you let go of the gas.
While the game is stable at 120 FPS, pushing beyond 144 FPS introduces severe physics instability. For the average player, the 120 FPS configuration is the recommended standard for a bug-free modern playthrough. gta san andreas 120 fps mod
Mention if you're using the or the Original 2004 version. Vehicles stop instantly when you let go of the gas