DIC Fuel Range Issue?
 

I recently checked my fuel range on the dash and noticed an issue. I’ll drive to work and it will read 156 (for example) and when I start my car up after my shift it'll read 160? And as the car is warming up it'll maybe even hit 164. Not sure why this is happening anybody experience this before? Is this normal?

My semi-educated guess: Fuel gauging is not perfect and may vary depending on how fuel is distributed in the two tanks. A range difference of 8 miles usually represents 1/4 to1/2 gallon, which is not a lot of error for an 18.5 gallon tank.

Sounds normal to me. Don't depend on the range to be exact. Within 20 miles is probably a safe bet. I think the low fuel indicator comes on at only 30 miles.
The range is calculated using 'recent' parameters so that it will change fairly quickly based on your current usage. It could be WAY off if you go to the track and the range data is still based on your recent 20+ mpg from a highway trip.
Also, there are two fuel tanks on the C5 and a transfer pump to move fuel from one to the other. So when you first start it your fuel level could change quite a bit as the transfer pump moves fuel around. Not sure if that would affect the range or not.

Right on! Would this mean its normal for the fuel gauge to move up aswell? Didn't mention that in the original post.

Yes. My gauge goes up as I start driving the car.

Same here. When I start mine, it always shows lower than when I put it away. Then as I drive it moves up slightly.....