I got about the same results. Speaking of EVIC, mine showed I was getting 17.6 mpg when I filled up. I did a hand cal and it was 17.589...not to shabby either!

 

I've driven the truck ~50 miles past when it said low fuel. It goes to low fuel when it thinks you only have 30 miles left. I keep pushing it just to see how far I can get. I still only got 30.5 gallons in.

That means I could probably get another 25 or so miles out of it, meaning it has about a 75 mile range, assuming 16mpg. That's over 4.5 gallons after it says it's low fuel (and doesn't display a range, not when the light comes on).