engine.mblurscale 0 -> Use to disable motion-blur
engine.mblurintensity 0 -> Use to disable Blur Entirely (works in conjunction with the above command)
graph.setfastrunspecialefx 0 0 0.0 -> Removes blur while running fast
*Keep in mind that removing blur will impact framerate a bit but it's worth it, IMHO.
engine.bloommultiplier 0 -> Turns bloom off
engine.grassuserdistance 0 -> Removes Grass Entirely (can help with framerate)
engine.farplane 1200 -> The number relating to the draw distance. The default is 1200. Try setting it to 800 or 500. Improves framerate though you'll see tons of draw-in at lower numbers.
engine.dstfarplane 6000 -> This should completely turn off far-away rendering, improving the framerate significantly; again, experiment a bit - on PCs default is 6000.
engine.stencilshadows 0 -> This will disable shadows entirely. Again, another help to framerate.
graph.enablefog 0 -> Disable the fog in-game (another framerate booster in some instances)
cam.bank.move 0 -> Remove warbling of cameras as you run (helps reduce your need to vomit)
You just have to play and see what you're comfortable losing and/or keeping from an IQ perspective to boost framerate. I have not been able to disable the depth of field of effects in the PS3 version. The engine.useDOF 0 command does nothing. You still get a ridiculous amount of DOF in the background. For comparisons sake, here's the PS3 and 360 versions at default levels:
PS3 vs 360
It's one of the reasons I want to check out the 360 version and compare the two. The various screens I've seen of the 360 game (and the videos I've watched) seem to show off far better lighting effects as well. If I like it more, I'll likely trade up as I'm only about 4-5 hours in so far.