Leaked document indicates how far the upcoming plug-in crossover can travel on battery power alone.

Subaru will make its first assault on the plug-in hybrid market next year with the XV Hybrid, and new government documents from the USA indicate it should offer over 40 kilometres of all-electric range.

The filing, sourced from the California Air Resources Board (CARB), rates the Subaru Crosstrek Hybrid's all-electric range at 25.65 miles (41.28km) – 'Crosstrek' is the XV's name in the US.

According to Autoblog, the XV Hybrid will share its plug-in hybrid technology with the Toyota Prius Prime, a PHEV version of the long-running hybrid nameplate that is offered in overseas markets.

However, the 2.0-litre naturally-aspirated boxer engine under the bonnet will be a Subaru unit, and like the wider range (bar the BRZ sports car) the XV Hybrid will feature all-wheel drive.

By comparison the Prius Prime lists an EPA-estimated electric range of 25mi (40km), though the 'equivalent' urban figure is rated at 26.273mi (42.282km) – the latter incorporates the parallel use of electric and combustion power.

It's unclear how big the XV Hybrid's battery will be, though it's very likely it will be around the same 8.8kWh capacity as the Prius Prime.

The new model is expected to be revealed in Crosstrek form before the end of the year, so stay tuned for all the latest.

Australia

Earlier this year at the New York motor show, Subaru's local boss, Colin Christie, told CarAdvice the upcoming XV and Forester hybrids are likely starters for Australia in the near future, to address the gap in the local electrified line-up and pending emissions regulations.

"We don’t have exact dates and times, [also] not sure which tech will go into the cars, but Subaru has made it clear that they are moving down the hybridisation path and moving down the electric path," he said.

"Hybrids are still quite a small volume in the Australian market, but we see them as supplemental to our sales so we will have our 2.5-litre direct injection in case of the Forester, and then the hybrid will be an incremental model."

"There are customers out there looking for hybrid vehicles more and more, still relatively small numbers but that will grow and we are seeing more demand increasing in some areas, but at the end of the day it’s a future tech story and a step towards electrification, and a natural step in the journey for the brand," he added.

Subaru has offered a hybrid version of the previous-generation XV in overseas markets, such as its home of Japan, though it was never brought Down Under.

The standard XV continues to be something of a sales success for the Japanese brand, consistently ranking amongst the top sellers in the small SUV segment. For the month of October, the Impreza-based crossover managed 916 registrations, putting it behind the larger Forester (1792) in the brand's line-up.

Year-to-date, the XV has posted 11,419 registrations locally, making it Subaru Australia's most popular model by some margin – both the Outback and Forester are around 2000 units behind in their YTD tallies.

Which electrified small SUV is your pick? XV Hybrid or Kona Electric?