well its sorta like a basic potentiometer, like a radio volume ****, so empty it should be high resistance and full should almost be none, probably less than 5 ohms. This site explains the science of it and it might give a better picture------> http://auto.howstuffworks.com/fuel-gauge1.htm

As to the specific specs I haven't seen them posted anywhere yet.

 

I looked some different models up on autometer and some are totally backwards like some are 73 empty and 10 full and then another said 168 empty and 16 full. Maybe it will say which one you are supposed to have in the owners manual. Ive never looked up that information for any of my vehicles