If I recall correctly, I got out about 2.5 gallons when I drained my coolant system from the radiator. That leaves 2 quarts in the system I think.

 

Thanks! I found a reference there are 13.1 quarts total of coolant for my truck, so that would be pretty close.

If I'm thinking right, I can just use 6.5 quarts of the concentrated dexcool after flushing with water, then the rest will just need topped off with water to finish it out.

 

Just add 1 gallon of water and 1 gallon of concentrate then mix the rest by hand in 50/50 to fill. You don't want to over or under shoot too much.

 

I changed my coolant in my 2017 V6 from the Radiator
I was definitely over 2 Gallons back in.
Had the Thermostat go after that.
Would of been nice to do all at the one time looking back at it

 

Thermostat took me a lot less time than the flush honestly. If I'd just filled it back up probably would've been sufficient... Coolant looked great. But now the whole system is fresh, so I guess that's a plus.

 

Back in the day, I would drain the system through the radiator and refill with fresh water. Drive around until it heated up and then drained again. If it were particularly dirty I would use a radiator flush" chemical then a rinse before the final fill. Not sure how that would work in today's trucks.