Parts for your 2018 Subaru Impreza-Drive belt

2018 Subaru Impreza Drive Belt — What It Does and When to Replace

Technical references for this model — the 2018 Subaru Impreza Owner’s Manual, Subaru FB20 engine service literature, and mainstream belt catalogues from Gates and Dayco — confirm the car runs an external multi‑rib accessory drive belt (often called a serpentine belt). The FB‑series 2.0‑litre engine uses a timing chain (so there’s no timing belt), while the accessory drive belt powers key ancillaries.

On a 2018 Impreza, the drive belt’s main jobs are to spin the alternator and the air‑conditioning compressor. Power steering is electric on this model, so there’s no hydraulic pump on the belt, and the water pump is driven internally, not by the accessory belt. Even so, this unassuming belt is vital — if it slips or breaks, charging stops, the battery light pops on, and A/C performance drops to nothing.

As part of regular servicing, the belt should be inspected under the bonnet for wear and correct tension. Subaru’s guidance is largely condition‑based: check it at routine service intervals and replace when wear shows. In Aussie and Kiwi conditions — heat, stop‑start traffic, dust and the odd spirited weekend — many belts comfortably last 100,000 to 160,000 km, but it’s smart to act on condition rather than a fixed kilometre figure.

• Common wear signs: fine cracking across the ribs, frayed edges, missing rib sections, glazing/shiny patches, rubber dust, or chirping/squealing on start‑up.
• Contamination: coolant, oil or power steering fluid (on other models) quickly degrades belt rubber