I have been driving with the DSC off and haven't noticed any difference. What should I experience with it off as opposed to on and under what conditions?

 

No difference until you start sliding. The car will apply brakes at the appropriate wheel to keep you pointed generally forward.

 

Does the rx8 dsc actually use brakes? I thought it was just cutting throttle & a limited slip.

 

It's both, depends on the situation.

 

If DSC is off, I imagine the TCS must be off, too.

 

There are two stages for the dsc and TCS. I suggest reading the manual. Pressing it once allows for 1 setting of that stability control system be be turned off. Pressing it again turns it back on. Pressing and holding the button for a few seconds turns everything except ABS off. It can not be enabled without turning the car off and back on again. My 2 cents, no reason to turn it off while driving on the street. It’s more of a helper with regular tires and brakes. If you have track pads and non DOT tires then the system can cause problems. At that point is when I suggest turning it off. With that setup you wouldn’t be on the street anyways.

 

Turning off the first stage is enough to stop the engine cut when you get bogged down in soft gravel / sand. Unless you want the car to go sideways you shouldn't have to disable the whole thing, but if you are on a very low traction surface you might have to. I realize 99% of people have never been on a dirt road and they can disregard that.