There is a stretch along I-70 in Utah of about 100 miles between Green River Utah and Salina Utah that goes through the San Rafael Swell and several canyons. The drive is surreal, gorgeous, and completely devoid of service stations. I truly recommend filling up in Green River or Salina before starting out, as it is a long walk of shame to a gas station.
When do you think you should feel the gas tank? When the tank gauge shows 1/4 full or when the fuel light comes on?
I always get anxious when the gas levels drop and will almost always refill prior to 1/4 empty. Fish, on the other hand, likes to see how far the car will get after the fuel light comes on.
According to the internet, I am right. Going below 1/4 tank dredges up all the sediment and goo in the gas tank and puts it into your engine. Fish needs to refill sooner.