It's about time I understood analogref(Internal)

Currently I have a voltage divider using a 2.2kohm resistor. I measure the board when its not connected to the relays at 4.36v.

The minimum voltage put out by the lm335 to the analog pin is 2.33v which equates to -40. the maximum being 3.73v which equates to 100

I use both of these meximum ranges to signify different things in code. So the total range for the sensors is 1400mv

what would analogref(2v56) give me?