Also known as: cb18, 1.8 turbo boxer, 1.8 dit, levorg engine, forester 1.8
Subaru's newest flat-four — a 1.8-litre turbocharged, direct-injected engine introduced with the current Levorg and now in the Forester and Outback in some markets, and the company's first genuinely new boxer architecture in a decade.
It uses a lean-burn strategy with a very high compression ratio for a turbocharged engine, aimed at efficiency rather than the outright output the EJ and FA turbo engines chased. That changes what its normal operating data looks like: fuel trims and knock-sensor activity read differently from an FA20F, and interpreting one by the other's expectations will mislead.
It is recent enough that no failure pattern is established, and saying so is more useful than speculating. What carries over from the rest of the family is the layout's consequences — head gasket leaks presenting as external weeping rather than internal mixing, and access that makes routine work larger than it looks.
Cars fitted with this engine
3 generations, across 1 make. From the authored catalogue — an absent car means the catalogue has not reached it, not that the engine was never fitted.
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Posted about this engine
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Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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