well, in a way, lfs does support multicore: I'm almost sure the sound runs in a different thread than the game.

Quote from Linsen :

Also, there is, imho, no immediate need for dual core support. LFS runs fine in rather high resolutions on a E6300 with a halfway decent graphics card. I've got a [email protected] GHz and a 7600GT. With all graphics settings maxed out and AA and AF overkill, I get an average of around 55 fps with a full grid of cars on 1680x1050 resolution and my fps rarely drop below 50 (even on rallyx courses).

You need to stop thinking in general games terms. LFS does a hell of a lot more physics calculation wise than most other applications. If you can dedicate an entire thread, and ergo an entire core, to purely physical calculations (so that calculations dont have to stop in order to draw to the screen, etc.), you'd be able to run at a far higher resolution, only asking the physics thread for information when it's needed (such as where are the cars x, y and z right now).

Oh and as a final rant, fps is not a good measure of performance.