Join Date: Jun 2006
Location: Eastern ON Canada
Car: 07 OBW 2.5i D-4AT
Feedback Score: 7 reviews
The 2013 uses the "blue" Subaru premium super coolant. It's supposed to last up to 11 years.
If this is for the occasional "top up", given the long time frame, why not pick up a jug of the Subaru coolant at your dealer? That way, there's no risk of mixing formulations, and not even a potential for impact (as limited as it might be) in case of warranty claims related to the cooling system.
The coolant comes pre-mixed (50/50).
(Perhaps stop by the service department of your dealer and speak to the Subaru mechanic. Many dealers are now using the blue coolant only, even for earlier model year cars that originally had the green fluid. When refilling cooling systems they usually end up opening a second gallon jug, but using only a small part of it -- the rest is kept in the shop and used for "top ups" (usually done during unrelated service, oil changes etc). You might be able to get one of the partial jugs, or they might fill a clean container (perhaps a 2 quart size), just for asking.)
incidentally, the blue Subaru super coolant jug I have says it contains "ethylene glycol" (in the "in case of emergency/medical warning section on the rear label).