The Polestar optimisation applies exclusively to the range-topping XC90 T8 plug-in hybrid. Combined power has risen by 14bhp to 415bhp, and torque has increased by 44lb ft to 500lb ft in total.
This culminates in a 0-62mph sprint time of 5.5sec, which is a tenth of a second faster than the standard T8. This is said to turn the XC90 into a more enjoyable car to drive at pace.
The Polestar engine modifications are claimed to have improved throttle response, while a new gear hold function - which prevents mid-corner automatic gearchanges - should prevent the car's balance from being upset under lateral load due to unwanted shifts.