The system, which uses kinetic energy recovery braking to assist the combustion engine, is claimed to deliver fuel efficiency savings and emissions reductions of as much as 15%.
Models featuring the technology will use a ‘B’ prefix, to separate them from the petrol, diesel and plug-in hybrid versions already available. B-badged cars can come with either a diesel or petrol engine, and Volvo expects these versions to become the most popular.
The mild hybrid versions of the XC90 that will be available initially are a B5 petrol or diesel and a B6 petrol. The powertrain will be gradually rolled out to other models, starting with the XC60.
Only mild revisions have been made to the XC90's exterior styling for 2019. It gets a new-look front grille, additional paint choices and new alloy wheel designs.
Inside, it gains Android Auto smartphone mirroring for the first time, in addition to the Apple CarPlay functionality already present on the old car.
Volvo will begin taking orders for the refreshed XC90 later this month. It will arrive in British dealerships this summer, although pricing has yet to be confirmed.