For a 2013 Subaru Outback, use Subaru Genuine Long Life Coolant Type 2 (SLLC Type 2) or an equivalent ethylene glycol–based, silicate-free coolant, mixed 50/50 with distilled water.
The Outback’s cooling system relies on aluminum components and requires a coolant formulation that protects against corrosion and deposits. Subaru recommends a long-life coolant (Type 2) and a 50/50 mix with distilled water. If you can’t find the OEM product, choose a high‑quality HOAT/OAT coolant labeled as compatible with Subaru engines and clearly silicate‑free. Always confirm with your owner’s manual or a Subaru dealer if you’re unsure about exact specifications for your VIN and region.
Approved coolant options
Before selecting a coolant, note that Subaru officially endorses the OEM option and allows high‑quality equivalents that meet the same technical standards (silicate‑free, ethylene glycol–based, compatible with aluminum engines). Look for language indicating compatibility with Subaru or Asian‑market engines and ensure the product is silicate‑free.
- Subaru Genuine Long Life Coolant Type 2 (SLLC Type 2) – ethylene glycol–based, silicate‑free, designed for Subaru engines. Typically sold as a premixed 50/50 solution with distilled water.
- High‑quality HOAT/OAT coolant that is specifically labeled as compatible with Subaru vehicles and aluminum engines, and that is silicate‑free. Verify it is appropriate for use in Subarus and does not include additives that could harm gaskets or seals.
If you’re unsure whether a coolant qualifies, consult your owner's manual or contact a Subaru dealer for the exact specification required for your vehicle.
How to mix, bleed and maintain
Before starting, remember that the recommended practice is a 50/50 mix of coolant and distilled water. Properly bleeding the cooling system after a service is essential to prevent air pockets that can cause overheating.
- Use distilled water to dilute concentrated coolant if you purchase a concentrate; premixed 50/50 coolant is acceptable to skip dilution.
- Drain the old coolant from the radiator and engine block, then flush with distilled water if performing a full replacement or if the coolant is contaminated.
- Fill with the 50/50 coolant mixture, then start the engine with the heater on high to help bleed air from the system. Monitor the temperature gauge and the coolant level, topping up as needed.
- Keep the expansion reservoir between the MIN and MAX marks during the process; avoid overfilling.
- Inspect hoses and the radiator for leaks and ensure there are no air pockets around the thermostat and radiator cap; use any bleed valve if equipped.
- Dispose of used coolant in accordance with local regulations; used coolant is toxic and should be recycled by proper facilities.
When in doubt, do not mix different coolant types or colors. If you’re not comfortable performing a full flush and refill, have a qualified technician handle the service to ensure proper bleeding and level accuracy.
What to avoid
Color is not a reliable indicator of compatibility. Do not use coolant with silicates or inappropriate additives in an aluminum Subaru engine, and avoid “universal” antifreeze formulations that aren’t explicitly labeled as Subaru-compatible or HOAT/OAT with silicate-free formulas.
Summary
For a 2013 Subaru Outback, the safest and most reliable choice is Subaru Genuine Long Life Coolant Type 2 or a compatible silicate-free ethylene glycol–based coolant labeled as HOAT/OAT and approved for Subaru engines, used in a 50/50 mix with distilled water. Adhere to the owner’s manual for replacement intervals and follow proper bleeding procedures after service. When in doubt, consult a Subaru dealer or certified mechanic to confirm the exact specification for your vehicle.