The weird issue that I have with this game is that GOG wrapper works great, but for some odd reasons at higher resolutions (1024x768 and 1600x1200) I get FPS drops when taking orders and looking on the sides (Shown on the attached screenshot). DgVoodoo works better, but the menu's looked not as good and some artifacts when forcing a higher render res. Any sollutions or at least explanation on why this is happens, please?
https://i.imgur.com/BmU2pts.png

I have the same issue, when I open the large map I have lag, when I take a order I have lag and when I watch left or right I have lag and I dont know why, if someone can help it would be nice because I want to enjoy playing this game.

tweak it from 3d settings. if you search "Hard Truck 2: King of the Road GOG version fps problems" you will see a gog support page that helps some issues about it. i thought changin it to high performance card would work but it didnt. try turning on vsync since its locking the game 60 fps which game works at normally and multi card setting to single. this is for nvidia of course, if ati/amd then it could be something else. tweak it from there, try each setting, close technologies that werent present at that date etc. you'll work it out ^^