I think even with DirectX 9, LFS could probably BENEFIT from having that engine, regardless if it wasnt using any of the DX9 features that DX8 doesn't have. Personally I think LFS would have an FPS increase for users with DX9 cards (and I am sure the majority of us have those). For how simple and bland LFS looks, FPS sure isn't very 'good' compared to the pimped out DX9/DX10 games using proper hardware. Hell even on autocross, systems that play DX9 games at very high FPS suffer in DX8 LFS Auto-x. I just don't understand why it has to be this way.
Perhaps it is a very crude graphics engine that doesn't make use of any DX9 powered cards... feels more 'raw' than anything else. I am sure LFS could run so much smoother if it was optimized and could be run under DX9. Sadly, I don't think we'll ever see that happening, and it will always be behind in this department. I think Scawen has the most experience with DX8 games, since that is the engine he is most familiar with even with his other previous games. Not sure if he has looked at DX9+ at all, but I hope he has... and hope it is easy to pick up on when the time comes.
Using the whole "dds" stuff under DX8 just doesn't feel like there is any gain from it. I think Scawen really needs to utilize such features for textures when there is actually a better renderer in place of DX8.... else it just doesn't feel like it helps.
I mean, newest games have all these crasy AA, AF, blurring, reflections, lighting, etc... and they still can run fine with the proper hardware. Yet LFS has very rudimentary graphics and can be hurt in some occassions... like with smoke and LOD issues. And LFS is still very low detail out of the box. Not just its textures, but also the car models and other objects are very low poly.