You don’t get a second chance to make a first impression. That’s why Polestar, Volvo’s new electric performance subsidiary, used its first vehicle as a rolling showcase of the brand’s technology. We took the $156,500, 600-plus-horsepower plug-in hybrid (PHEV) Polestar 1 coupe on a 110-mi (177-km) drive in the Bay Area in late October. Axle Stenberg, technical concept leader, summarized the Polestar 1’s extraordinary recipe.
“First you take an SPA car,” he said, referring to Volvo’s Scalable Product Architecture (SPA), the platform underpinning the XC90, XC60 and S90. “Now you add the biggest combustion engine we had.” That means a supercharged/turbocharged 2.0L 4-cylinder mill that produces 326 hp (243 kW) and 384 lb-ft (521 Nm). The internal-combustion power is distributed strictly to the front axle via an 8-speed automatic gearbox. “Then we added as much battery as we could fit.”
In the Volvo brand’s T8 PHEVs, an 11.4 kWh-pack is loaded into the central tunnel from the A-pillar to just in front of the second-row seats. The Polestar 1’s energy storage is tripled to 34 kWh with 96 cells in the tunnel and 192 placed over the rear axle. “The car should feel like an EV, and you should be able to use it to that end, not just where you can barely get back and forth to work on electricity,” Stenberg said. That required two separate battery packs in a 400-V system. Polestar expects an EPA range rating of 60-70 mi (97-113 km). In our drive, we covered 78 mi (126 km) with minor use of the gas engine before the battery was depleted.
Showing off the tech
In dramatic style, the wall between the back of the battery pack and the diminutive 4.41-ft2 trunk is transparent. It exposes orange-colored high-voltage circuitry. The idea was introduced late in the design process by Thomas Ingenlath, Polestar’s CEO, who previously held chief design positions at Volkswagen and Volvo. “The engineers and project guys thought I was nuts,” he said.
Where the technology design took a giant leap is in using two 85-kW electric motors, one per rear wheel. This allows Polestar 1 drivers to select the Pure mode on the dashboard and turn it into a capable, rear-wheel-drive, 232-hp EV. On our drive, we put the Polestar in Pure mode and stomped on the accelerator, but the engine remained dormant. Although a heavy vehicle at 5,170 lb (2,345 kg), launches from the two motors combined 354 lb-ft (521 Nm) were what you would expect from a performance-oriented EV.
“The two electric motors are individually handling one of the rear wheels, and there’s no differential,” Stenberg said. “There’s no mechanical mixture between them. That means that we can add true torque vectoring, momentarily adding or subtracting torque on the wheels.” The effect was effortless cornering on twisting, fast-moving mountain roads from San Francisco to the Pacific and back to Burlingame, Calif.
There’s no linkage between the electric motivation on the rear axle and the ICE power in front (the tunnel is loaded with batteries). When we selected Power mode, both systems engaged to produce a combined 619 hp/738 lb-ft (462 kW/1000 Nm). The feeling of getting pulled by the engine and pushed by two electric motors with torque vectoring was exceptional. A 15.9-gal fuel tank mitigates any range anxiety, although the Polestar is equipped with a 50-kW CCS quick-charger for one-hour refills of the battery packs.
Spiffy design and carbon fiber for stiffness
The Polestar 1’s pièce de résistance is its liberal use of carbon fiber construction. Using the same design strategy that exposes the battery cables, Polestar reveals the carbon fiber pattern in the bumper, tread plates and dashboard inlays. The design – an homage to the classic Volvo P1800 – would not have been possible without using carbon fiber. The car’s strong hips are fundamental to the design of the 2+2 GT’s sport cabin.
“The carbon fiber enables us to have this low silhouette, the small sections of the roof, as well as the sharp feature lines,” Stenberg said. He explained that metal parts of the body could be replaced with carbon fiber feature lines ground to a radius of about 2.7 mm (0.10-in). “You can’t press steel to that tight diameter we have on the car’s rear hip line,” he said.
The roof section from the base of the A-pillar to the C-pillar side-member consists of a rigid carbon-fiber tube baked into the outer structure of the pillar construction. Without carbon fiber, the roofline would have been higher. The inner-body side panels, outer-body side panels, doors, front fenders, hood, trunk and rear parcel shelf also use carbon fiber. There is no visible antenna. Small pieces of carbon fiber joined separate chassis parts from the SPA platform to reduce the wheelbase and add stiffness. The suspension was completed with Ohlins performance dampers using manual clickers, Akebono brakes and 21-in rims.
The weight saving from carbon fiber was about 500 lb (226.7 kg), mitigating the mass of the two battery packs that together weigh 754 lb (342 kg). With the engine up front and the larger battery pack positioned over the rear axle, the weight distribution is 48/52% F/R. Given this balance and the Polestar’s double-power strategy, it felt lighter than its official curb weight of 5,170 lb, and the steering feel was taut and responsive. That feeling is partly due to the quietness and low-vibration operation of the electric drive.
Stenberg explained that the supercharger helped avoid turbo lag, while the electric motors provided instantaneous torque. “We could probably lose the supercharger and put an even bigger turbocharger on the combustion engine and start to optimize,” he said. After the battery was depleted, the GT reverted to a front-wheel-drive sedan powered by a relatively modest 4-cylinder, 2.0L engine.
It rumbled and vibrated as we piloted the Polestar 1 through narrow, curvy roads and the car’s hefty weight was made apparent. The Polestar also uses an integrated starter-generator that works as a high-voltage generator and as a starter-motor to provide an extra boost of 68 hp (50 kW). It does not directly power the wheels and can only be used when the combustion engine is running.
Only 1,500 examples of the Polestar 1 will be produced, with 500 headed to North American customers. The Polestar brand, a subsidiary of Volvo, is owned by Chinese automaker Geely. The Polestar 1 will be mostly hand-built in Chengdu, China. The automaker’s follow-up vehicle, the all-electric Polestar 2 sedan, will be produced in Luqiao, China with production volume in the “tens of thousands” globally per year. The Polestar 2 begins production in February, making 2020 a busy year for the performance electric brand.Continue reading »