If I recall correctly, the tank on a 1500 hjolds about 5.2 gallons.? Tonight after work, I put 5.21 gallons in it. I have about a 35 mile ride home from work, and when I left work tonight, the gauge read below empty. But I figured what the heck, even tho I was getting horable milage on this tank, I figured I could still make it home. I did, but was cutting it close!