Subaru will end production of its original e-Boxer mild-hybrid powertrain, currently offered in the Australian-market Crosstrek small SUV, as it increasingly turns to Toyota hybrid technology.

After more than a decade of development, the Japanese automaker told Nikkei it will discontinue the mild-hybrid e-Boxer system, which it began developing in 2013 and first introduced in Japan in the 2018 Forester SUV.

"In light of the progress in electrification and the strengthening of environmental regulations, we have reviewed our product portfolio and have decided to discontinue the mild hybrid vehicle program," Subaru said in a statement, as reported by Nikkei.

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The e-Boxer mild-hybrid powertrain first arrived in Australia in March 2020, when the Forester Hybrid e-Boxer and XV Hybrid e-Boxer were launched.

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Both used a 110kW/196Nm 2.0-litre horizontally opposed ('boxer') four-cylinder petrol engine, a continuously variable transmission (CVT), and a 12.3kW/66Nm electric motor paired with a lithium-ion battery.

At launch, Subaru Australia claimed the e-Boxer's regenerative braking system and three drive modes reduced urban fuel consumption by up to 14 per cent in the XV Hybrid and 19 per cent in the Forester Hybrid compared with their petrol-powered equivalents.

The system could also drive on electric power alone at speeds of up to 40km/h. It remains available locally in the XV's successor, the Crosstrek, though Subaru hasn't confirmed when final Australian shipments will arrive.

The Japanese brand recorded the third-highest emissions liability of any automaker during the first reporting period under Australia's New Vehicle Efficiency Standard (NVES), which progressively tightens fleet-average tailpipe emissions limits.

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In place of the mild-hybrid system, Subaru will continue offering its newer 'strong hybrid' powertrains and battery-electric vehicles, relying increasingly on Toyota technology.

The two brands have long collaborated, jointly developing vehicles including both generations of the Toyota GR86 (née 86) and Subaru BRZ sports coupe.

In 2025, the sixth-generation Forester arrived in Australia with Subaru's 'next-generation e-Boxer' strong-hybrid system, combining a 2.5-litre four-cylinder boxer petrol engine with a 90kW electric motor and a Toyota-sourced 1.1kWh battery for a total system output of 145kW.

The new powertrain reduced the Forester Hybrid's official combined fuel consumption to 6.2L/100km across all three hybrid grades, a 0.5L/100km improvement over its predecessor.

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Subaru also abandoned development of its own plug-in hybrid (PHEV) technology in 2023, confirming it would instead source future systems from Toyota.

The partnership has since expanded to electric vehicles. The Toyota bZ4X and Subaru Solterra – both built by Toyota – were launched in Australia in 2024.

The related Toyota bZ4X Touring and Subaru Trailseeker duo followed this year.

Subaru's Uncharted electric SUV, launched locally in April, is twinned with the Toyota C-HR EV, which is due to arrive in Australia during the first half of 2027.

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