Yup
CAR GEOMETRY - the quality of the cars
TRACKSIDE GEOMETRY - the amount of scenary you see on the track
TEXTURE DETAIL - the quality of the textures (medium gives very good quality by the way
PIT CREW (self-explaining, but why does it affect the fps ???) - I guess it does when your in the pits with a load of other cars, or are using an external camera that looks over the pitwall so they have to be drawn
ADVANCED LIGHTING - when you go in shaded areas of the track you get fancy lighting effects like the lights in your cockpit are clearer etc.
ENVIROMENT MAPS - fancy graphical thing that makes it look stunning. sadly you need a stunning computer to play it on full though
BUMP MAPPING - another fancy graphical thing to do with textures. doesnt effect performance all that much. i would enable it.
REFLECTIONS - the reflections quality. high tends to be a bit much, but low seems to look ok
SHADOWS - the quality of the shadows
Hope this helps.