I have a '98 Z-28 Camaro as a daily driver.It's automatic. 
A friend of mine and I decided to go to Vegas the other day.  
To avoid traffic, we left around 4 in the morning. I filled up the tank and immediately got on the freeway. 70-75 mph average speed, all the way  to Baker.No traffic. We decided to pull over at a gas station. Get some coffee.  
Now, here's the funny thing:  
We had travelled exactly 164 miles from Pasadena to Baker. The gas gauge showed a little more than 3/4.  
Out of curiosity, I've decided to fill up the tank. 3.88 gallons. It wouldn't take any more. 
That's over 41 miles per gallon! 
Is that normal? I usually get around 300 miles with a full tank, city+hwy... 
  
The car is NOT for sale....