Parts for your 2023 Subaru Impreza-Spark plugs

2023 Subaru Impreza spark plugs — purpose, servicing and when to replace

Technical sources such as the Subaru 2023 Impreza Owner’s Manual, Subaru Service & Warranty Handbook for AU/NZ, and OEM plug catalogues from NGK and Denso specify iridium spark plugs for the FB-series petrol Boxer engines used in this model year. As a petrol, spark‑ignition vehicle (FB20/FB25), the 2023 Subaru Impreza absolutely uses spark plugs, and they’re a key service item.

In the Impreza, each spark plug ignites the air–fuel mix inside its cylinder, ensuring smooth starts, crisp throttle response and proper fuel economy. The factory iridium plugs are long‑life and work with the coil‑on‑plug ignition to deliver a strong, consistent spark under all conditions, from chilly morning commutes to highway runs across Australia or New Zealand.

For routine servicing, owners will find the recommended replacement interval for the 2023 Impreza’s iridium plugs is typically around the 100,000 km mark (time-based limits may also apply). Those intervals can vary with market, fuel quality and driving style, so following the Subaru maintenance schedule listed in the handbook is the safest bet. If the car sees lots of short trips, dusty conditions or heavy loads, earlier inspection is wise.

When changing plugs, using the correct OEM-specification iridium type and heat range is important. Fit all four at once, confirm the gap is to spec (fine-wire iridium gaps are usually pre-set), and tighten to the factory torque listed in the service manual. Because access around a Boxer engine can be tight, careful tool selection and proper torque are essential, many owners prefer having a qualified technician handle the job. It’s a good time to check coil boots, apply dielectric grease where appropriate, and inspect for oil or coolant leaks that could foul a plug.

Common signs the Impreza’s spark plugs may need attention include:

• Rough idle, hesitation or a drop in power
• Poorer fuel economy and lazier cold starts
• Check Engine light with misfire codes (e.g., P0300–P0304)
• Noticeable pinging under load or increased emissions

Keeping the plugs healthy helps the 2.0L or 2.5L Boxer run cleanly and efficiently. Refer to Subaru’s official schedule and the Owner’s Manual for the correct plug specification, and stick with reputable brands that match the OEM part number listed for the 2023 Impreza.

Popular questions about 2023 Subaru Impreza spark plugs

How often should spark plugs be replaced on a 2023 Impreza?
Subaru’s schedule for the 2023 Impreza typically calls for iridium spark plug replacement at around 100,000 km, with time-based limits also applying. Driving in harsh conditions, frequent short trips or lower fuel quality may justify earlier inspection. Always follow the intervals and specifications in the Subaru Owner’s Manual and local Service & Warranty Handbook.

Which spark plugs does a 2023 Impreza use?
The 2023 Impreza’s FB-series petrol engines are specified for OEM-grade iridium spark plugs with a Subaru-approved heat range and reach. The exact part number can vary by engine variant (2.0L vs 2.5L) and market, so it’s best to match the plug to the VIN and consult the Subaru parts catalogue or the manual to ensure the correct fitment.

What are the symptoms of worn spark plugs in a 2023 Impreza?
Typical symptoms include rough idle, hesitation, slower starts, reduced fuel economy and the Check Engine light with misfire codes. If any of these appear, have the plugs and ignition coils inspected and replace the plugs as a complete set using the correct iridium specification.