With performance tweaks provided by in-house tuner Polestar, the XC90 T8 ‘Twin Engine’ plug-in hybrid is not just the most powerful production Volvo ever built, it’s an example of how automakers are generating power and performance using hybrid technology. With Polestar upgrades, the T8 model produces a combined 421 horsepower and 501 pound-feet of torque in hybrid mode, notes alternate-vehicle Web magazine Green Car Reports. That’s compared to 400 horsepower and 472 pound-feet in the standard XC90 T8. It’s enough to move the full-sized tall wagon to 100 km/h (62 mph) from zero in 5.5 seconds, putting it in sports-car territory. Buyers will be able to order the T8 ‘Twin Engine’ with the Polestar Performance Optimization package in October.