Volvo is spinning off Polestar into a standalone brand for high-performance electrified cars, but that doesn’t mean the Swedish brand born out of racing won’t be tuning Volvos anymore.

Polestar will also continue to offer optimization for Volvo cars, under the new Polestar Engineered label. And the latest Volvo to get the Polestar treatment is the 2018 XC60—specifically, the XC60 T8 plug-in hybrid.

Using its tuning expertise, Polestar has managed to massage 421 horsepower from the XC60 T8’s plug-in hybrid powertrain. That represents a 21-hp bump over the standard XC60 T8 whose powertrain consists of a 2.0-liter supercharged and turbocharged inline-4 at the front axle and an electric motor at the rear.

With the standard XC60 T8 able to hit 0-60 mph in 5.3 seconds, the additional 21 hp should bring that time down even more.

2018 Volvo XC60 T8 R-Design with Polestar optimization

2018 Volvo XC60 T8 R-Design with Polestar optimization

Polestar didn’t just tune the XC60 T8 for more power. The company says it studied engine performance, throttle response, gearshift speed and hold, plus other areas to create a more fun-to-drive experience in everyday conditions. In particular, the tuner ensured more torque is delivered mid-range to ensure accessible thrust is on tap for daily, spirited driving duties. The 8-speed automatic transmission also shifts quicker and holds a gear longer when cornering with high lateral g forces to maintain balance.

With 421 hp, the XC60 T8 also matches the larger XC90 T8's output to represent Volvo's most powerful vehicles ever produced.

Pricing for the Polestar optimization will be announced closer to the market launch this fall. Installation is handled at the dealer.

Depending on the market, other XC60 trim levels—T6, T5, D5 and D4—will also be offered with Polestar optimization.