The carmaker recently revealed planned upgrades to its Nagoya Works Okazaki plant in Japan’s Aichi Prefecture, according to Japanese title Car Watch, announcing production would increase from 174,000 during 2013 to 212,000 during 2014 – a 22% rise.

Mitsubishi had initially planned around annual production of 21,000 Outlander PHEVs, and electric drivetrain components have been manufactured separately. Under new plans, these will be brought into the main production line, as it targets 50,000 units during the 2014 financial year.

The Outlander PHEV launched in the UK in April, priced the same as the equivalent top two trim levels with the 2.2-litre diesel engine and automatic gearbox. Set to have a fleet-heavy sales mix, it’s expected to account for 62% of UK Outlander volume and will increase its company car volume by 184%, the company said.

Demand has been so strong globally that the car has yet to launch in North America, and has only recently arrived in Australia. The Netherlands soaked up most of the first European cars, due to large financial incentives for plug-in hybrids, and almost all Dutch customers chose the PHEV over the diesel.

Okazaki’s additional production volume will be spread among the conventionally-powered Outlander and smaller ASX, which will grow their volumes from 80,000 to 86,000 and 64,000 to 76,000 respectively in the 2014 financial year. It means over a third of global volume (37%) for the Outlander will be the plug-in hybrid.