Specs: 2.00GHz core i3 and 4GB of ram. Intel graphics 520 and windows 7. Also I tried the game on windows 10 and it does run better but I hate the look of windows 10 soo yea
Small Grid pure with simplified collisions on, only ever have 1 car out at a time and never spawn the Wentward DT40L or T-series. You might get 10fps.
@Ngm has a bunch of mods that are fairly low on requirements. A lot of people cried about them being low quality but they should run on low-spec PCs just fine. You could try my Deep Earth, since it lacks terrain and the entirety of the map's detail level changes with your specs. However I poured so much stuff into that map I can't really say if it'll run comfortably for you. I usually get 40-65 FPS on average maps and Deep Earth gave me about 85, so take that as you will. Edit - with specs like yours you'll be pushing your computer really, really hard running anything beyond smallgrid. You can load up the world editor in smallgrid and play around with the stuff in there though.
VR_City is easy on the computer, but you should really have a quad core to run this game, and 4gb is not enough to really game with your OS.
Island maps, Desert maps and grid maps are your best bet. Been there done that. The less trees the better https://beamng.com/resources/simple_map.3470/ https://beamng.com/resources/vintage-autobahn.3395/ https://beamng.com/resources/desert-highway-updated-version-13-1.50/ https://beamng.com/resources/ssrb.523/ https://beamng.com/resources/endless-highway.1427/ https://beamng.com/resources/b-i-h-s-crash-hall.3205/ https://beamng.com/resources/bonneville-salt-flats-speed-week.1876/ https://beamng.com/resources/mt-shell.15/ https://beamng.com/resources/brutal-slope.351/ https://beamng.com/resources/crimson-valley.1674/ Crimson valley ran good on my old pc. https://beamng.com/resources/matrix-freeway.48/ https://beamng.com/resources/drag-strip.2205/
yea once ram prices go down I might try getting 8GB of ram, or if they even will come down that much this YEAR