Most modern Subarus use electric power steering (EPS) and do not require automatic transmission fluid (ATF) for the steering system. In older Subarus equipped with hydraulic power steering, ATF was used as the hydraulic fluid, but the exact specification varies by model year and market.
Subaru’s approach to power steering has shifted over time—from hydraulic systems that rely on ATF to electric-assisted steering that uses no steering-fluid fluid at the rack. This article explains when ATF is used in Subaru vehicles, how to tell which system your car has, and what fluid to use if you still have hydraulic PS.
Hydraulic vs electric power steering in Subaru vehicles
Below is a quick snapshot of how power steering types have evolved across Subaru’s lineup and era.
- Older Subaru models (roughly mid-1990s to late-2000s) typically used hydraulic power steering that requires ATF as the hydraulic fluid.
- Early- to mid-2010s models began adopting electric power steering (EPS) in many trims, reducing or eliminating ATF involvement in the steering system.
- Most current Subaru models (2020s) rely on EPS, meaning ATF is not used for power steering in these vehicles.
In practice, that means if you own a newer Subaru, you are unlikely to deal with ATF for the steering system. For older models with hydraulic PS, ATF specifications apply as part of the hydraulic circuit.
What fluid to use if your Subaru still has hydraulic PS
If your Subaru still uses hydraulic power steering, the fluid you should use depends on the model year and service guidance. Below is a general guide to what is commonly specified in Subaru manuals and service Bulletins.
- Dexron II or Dexron III ATF has historically been specified for hydraulic PS in many older Subarus.
- Dexron VI ATF is a modern replacement that is often acceptable where older Dexron II/III is specified; always verify against your owner's manual or a dealership bulletin.
- Some markets or specific engines may call for Subaru’s own PSF or a designated ATF variant listed in the service manual; check the exact spec for your vehicle.
Always consult your owner's manual or a Subaru dealer to confirm the correct ATF type for your model and year. Using an incorrect ATF can affect steering feel and the longevity of the hydraulic pump and rack.
How to identify whether your Subaru uses EPS or hydraulic PS
Identifying the system is straightforward with a quick check under the hood and at the steering column.
- Presence of a power steering fluid reservoir labeled “Power Steering Fluid” and connected hoses indicates a hydraulic PS system that uses ATF.
- Absence of a steering-fluid reservoir, along with a motor mounted near the steering rack, usually signifies electric power steering (EPS).
- Feeling the steering can also help: EPS often feels lighter at low speeds, while hydraulic PS may feel heavier and can leak if faulty.
If you’re uncertain, consult your vehicle’s owner’s manual or contact a Subaru service professional for a definitive determination.
Summary
The current trend at Subaru is toward electric power steering, which eliminates ATF involvement in the steering system. In older, hydraulic-PS Subarus, ATF is used as the hydraulic fluid, with Dexron II/III commonly referenced in older manuals and Dexron VI as a modern replacement option in many cases. Always verify the exact specification for your model and year in the owner’s manual or with a Subaru dealer, and use the correct fluid to maintain steering performance and reliability.