Running out of gas on an S10. I managed to pull that trick about a week ago. I made it 240 miles or 386 km. I was on reserve for approximately 50 miles or about 80 km. I routinely get about 42 to 44 mpg. I figure, unless I'm really pushing it, to have at least 40 miles once I hit reserve. When I fill up, just after it hits reserve, I'm usually putting in about 4.5 US gallons.