Yeah you need to add the T_, F_ and V_ yourself. I probably haven't explained it to well so I'll try again
Step 1: Outside of Centrafuse, Open up the SpeedFan Application
Step 2: Click Configure
Step 3: In the picture above you can see that the "CPU" field is highlighted (I've referred to these as 'items'). Press F2 with an 'item' highlighted you can rename it to whatever you want.
Step 4: In the above example, CPU would be renamed T_CPU. Once you have entered the desired name press enter.
Step 5: Repeat the process with each item you want to display, this works on the Fans and Voltages items as well.
Step 6: Ensure you click "OK" when finished to save all of your changes.
I hope that makes more sense out of it.

Have fun