2015 Mazda 3 coolant capacity?

[JeffKeryk]

I am about to service the coolant my grand nieces '15 Mazda 3. I believe the capacity is like 6 - 7 quarts?
Anyone know the radiator spill-and-fill amount?

Guess I will just buy 2 gallons... Thanks in advance.

 

[GSCJR]

Engine size?

 

[Kira]

In my limited experience, ~5 vehicles, the clever designers make 1 gallon spill forth when the radiator drain rooster is unscrewed.
Having 2 gallons on hand for a "radiator refresh" is the way to go.

Also, the total capacities, as listed in the Amsoil site for the 2.0l and 2.5l engines (w auto or manual transmission) are all close enough to 7 quarts to say so here.
They didn't provide a capacity for the radiator alone.

 

[TCL]

I used just shy of one gallon on my 2017 2.5.
A few ounces left. FYI....I drained it on ramps.

 

[MRC01]

The factory manual for my 2014 says 6.7 quarts of coolant for the 2.0 manual transmission. The auto takes 6.9 quarts and the 2.5 liter auto takes 7.2. When I drained it today (2.0 manual), about 6.7 quarts came out. Then I poured another gallon of distilled water through it until it drained clear. When I refilled it (using a coolant fill funnel with engine running), it only took 4-5 quarts even after running the engine at 2000-3000 RPM for several minutes, getting the Tstat to open, like the manual says. Then took a test drive, no change. It's full at the cap and the reserve tank is at the proper level. And the heater still works, it runs fine, no overheating.

But more came out than went in, so there must be air bubbles in there. I'll keep some distilled water and coolant in the back for a while. Same thing happened with the Subaru 2.5 liter, it took several hundred miles of driving before the coolant level finally stabilized.

 

[MRC01]

So I've been driving it like a teenager to vary the RPM through the full range and get the engine toasty warm. With the heater on high to get coolant flowing through the core. The fat hose entering the top of the radiator is easy to squish when it's cold, and after running the engine hard for a while to get it toasty warm, when I stop (leaving the engine idling) that hose is nice and tight. All as expected.

So it seems there is no air in the system. I must have overestimated how much coolant came out. I must have counted by accident some of the distilled water that I poured through the engine to flush it. It only took 4-5 quarts to fill it, which means about 2 quarts residual remained in the system, didn't drain. Some of that is normal/expected, but 2 quarts is 30% of the capacity which seems a bit much. The shop manual doesn't give the residual volume. I did the procedure IAW the shop manual and the car is running fine, and it's not drawing up any coolant from the reserve tank, level has stabilized, so even though it seems strange, it must be fine. I'll keep an eye on it for sure.