Out here in the west, it would be nice to have another 5-10 gallons. I like to take it easy and take backroads and there are lots of places where it can be 100 miles or more between stops.
On a trip last year, I saw a sign that said next gas 105 miles. gauge indicated I had a half a tank so figured it was no problem. Did not look at how many miles I had already gone.
In about 50 miles the gauge was close to empty and the warning light came on shortly after that. When I got to the station and filled up, I figured I had about .3 gallons left.
Now I always reset one of the trip odometers when I fill up and use that to gauge how much gas I have. The gauge is not to be trusted.
I'm not interested in being able to drive half the day, but a safe 350 miles would be nice.