They also make the accelerator responses quicker, and alter the settings of the automatic gearbox to provide faster gearchanges and prevent gearshifts during rapid cornering, which could unsettle the car. These quicker and more precise responses to driver commands not only make the driving experience more dynamic, they ensure the car responds predictably during high-speed driving.
The upgrades have been developed and designed by the engineers of Polestar and the racing drivers of Polestar Cyan Racing, the official motorsport partner to Polestar.
The maximum output of the D5 Drive-E engine is increased to 233 hp and 500 Nm of torque (up from 225 hp and 470 Nm), while the T6 Drive-E is boosted to 334 hp and 440 Nm (from 320 hp and 400 Nm).
Polestar Performance Optimisations have also been released for the D4 diesel and T5 petrol Drive-E engines in other Volvo models. Like the upgrades to the D5 and T6 engines in the XC90, the aim is to boost medium-rev performance and to make the car's entire drivetrain react more quickly and accurately to driver commands.
With the Polestar Performance Optimisation, the D4 Drive-E offers 200 hp and 440 Nm (up from 190 hp and 400 Nm), while the output of the T5 Drive-E is raised to 253 hp and 400 Nm (from 245 hp and 350 Nm).
The D4 Drive-E upgrades are available in the S60, V40, V40 Cross Country, V60 and XC60, and the T5 Drive-E enhancements are offered in the V40 and V40 Cross Country.
The price of the D4, D5, T5 and T6 Polestar upgrades is £835, including VAT and fitting. The work can be carried out at any authorised Volvo dealer, and should take about 30 minutes to complete. Finally, until the end of December 2015, all model-year 2005 to model-year 2015 all-wheel-drive Volvos can be upgraded with the Polestar Performance Optimisation at the discounted price of £620, saving £215.
The Polestar upgrades do not affect the certified emissions and fuel consumption figures, service intervals or Volvo warranty cover.