Parts for your 2020 Subaru Impreza-Drive belt

2020 Subaru Impreza Drive Belt — What it does, and when to replace it

Yes, the 2020 Subaru Impreza uses a drive belt. It’s a single serpentine belt on the FB20 2.0L engine that runs key accessories like the alternator and A/C compressor (and, on this engine family, the water pump is belt-driven too). Subaru moved to a timing chain for cam drive on the FB-series engines, so there’s no timing belt to worry about — but the accessory drive belt still needs periodic inspection and replacement. This is confirmed in the 2020 Impreza Owner’s Manual under Maintenance and service (checking the drive belt), and in the Subaru Service Manual (FB20 Engine > Mechanical > V-belt) which details the belt and automatic tensioner layout.

In everyday terms, that belt keeps the battery charging, the cabin cool, and coolant circulating. If it slips or breaks, the alternator stops charging and the engine can overheat quickly. That’s why belt condition is part of routine servicing.

Recommended care for Aussie and Kiwi owners is simple: have the drive belt inspected at every scheduled service. On vehicles that see lots of short trips, hot weather, or dust, be a bit more vigilant. Modern EPDM belts don’t always show deep cracks before they’re tired, look for fraying, glazing, missing ribs, or a chirp/squeal on cold start. Replace on condition, typically somewhere around 100,000–150,000 km, or earlier if any symptoms show.

This Impreza uses an automatic spring tensioner, so there’s no manual adjustment. If there’s noise, don’t just fit a new belt and hope for the best — have the tensioner and idler pulleys checked for play or roughness, and spin the accessory pulleys for bearing noise. Any coolant or oil contamination on the belt is a reason to replace it after fixing the leak.

When fitting a new belt, stick with the correct rib count and length, route it exactly as per the under-bonnet diagram, and use quality OEM or equivalent. A technician will typically unload the tensioner with a spanner, slip the belt on, then verify alignment across all pulleys. After install, it’s good practice to recheck alignment and listen for noise on first start.

Technical references: Subaru 2020 Impreza Owner’s Manual (Maintenance and service – Checking the drive belt), Subaru Service Manual (FB20 Engine – Mechanical – V-belt, tensioner and idler inspection), Aftermarket catalogue data from major belt manufacturers listing a 6‑rib serpentine belt for MY20 Impreza 2.0L.

• Watch-fors: squeal, battery warning light, A/C cutting out, higher temps in traffic.
• Service tip: replace the belt and any noisy pulleys together to avoid repeat visits.

Popular questions

Does the 2020 Impreza have a timing belt or a chain?
It has a timing chain for the camshafts, so there’s no timing belt service. The accessory drive (serpentine) belt is separate and still needs periodic inspection and replacement on condition.

How often should the drive belt be replaced?
Have it inspected at every service and expect replacement roughly between 100,000 and 150,000 km, sooner if there’s noise, wear, or contamination. Climate, driving style, and accessory load can shift that window.

What are signs the drive belt needs attention?
Cold-start squeal, visible fraying or glazing, intermittent battery light, reduced A/C performance, or rising engine temperature. Any fluid on the belt is also a red flag.