Size of my tanks?

Should be stamped around the neck or a tag on the end will have the capacity.

 

Hey Randy you most likely have 100 gallon tanks, they only can hold 95 gallons. Pick up tube in a tank is in fixed position and it will take 20 gallons to get just above this tube in each tank, if they would go all the way to the bottom they would pick up all the dirt and such from the very bottom of the tank. So it makes 40 gallons for both tanks like a reserve fuel and you were 10 gallons away from reaching it and stalling the truck on a side of the road. Always top it off as much as you can in the tanks then it will be 190 gallons total.

 

Most I've ever put in my 2018 t680 is 145 gallons and it was right on empty.

 

In my Cascadia I don't really start to worry until 100 miles after it hits zero.
If I'm really heavy.

When it indicates 1/2 about 70 gallons will top it off. At 1/8 I can put in about 130.
2 100 gallon tanks.

I call for fuel more often than I use the assigned fuel stops because the computer always thinks I have way less than I do, and I hate wasting my time to get 50 gallons.