Total gallons 2015 freightliner cascadia?

It should say on the tank at the fuel cap it should be stamped in to the aluminum tank

 

Yes you will need to check tanks but if it's a otr truck 2x100 gallon tanks is most common... Would depend on how they ordered it

 

I can tell you that a 2016 Cascadia will truck you down the road 170 gallons before it stalls out on Arkansas US-67.

Truth.

 

My 2015 is fairly stock. Has 2x100 tanks. The total draw is only 165 gallons though. I once (only once) ran out of fuel just as I pulled into a fuel island, set the brakes and was writing down my mileage. Anyways it took 167 gallons because I kinda topped off the tanks. True story.

 

Typically, a 100 gallon tank will hold 95 gallons. That of course is filling til all air is out and fuel is at top of filler cap. 95% of tank size is what most tanks hold. That info as well as tank size is usually found stamped into tank around fuel cap.

 

Because you can never 100% fill a tank, and even running out there is a few gallons left in the bottom of the tank. The first is simply the fill spout is never at the top of the tank, it's offset down the side a little. As for the other you don't want the pickup tube going all the way to the bottom to help prevent sucking in dirt to the fuel system.

Now yes, I've seen trucks with square tanks that do have the fill at the top most location, but those are rare in my experience.