The electric-gasoline hybrid system at the heart of BMW’s i8 Roadster and Coupe first impressed Awards judges back in 2014 when it not only won its category class, but also scooped the overall prize for the best powertrain of the year. The 1.5-litre three-cylinder unit has remained at the forefront of its category ever since, picking up trophies every year. In 2019 the combination of a turbocharged triple powering the rear wheels and an electric motor sending power to the front has remained as popular as ever with the International Engine + Powertrain of the Year panel, which has judged it this year’s very best hybrid powertrain.
“BMW has managed to transform a ‘humble’ 1.5-litre engine into a super-performer,” noted juror Nikos Kounitis. “The resulting drivetrain can easily outperform conventional engines with larger displacements in almost every aspect.”
Revamped during 2018 with an increased energy capacity lithium-ion battery (upgraded from 7.1kWh to 11.6kWh), the i8’s powertrain produces a total system output of 374ps. The turbocharged ICE contributes 231ps, while the e-motor produces 143ps, providing the i8’s LifeDrive architecture (aluminium chassis and high-strength carbon-fibre passenger compartment) with supercar-like performance. With peak engine torque of 320Nm at 3,700rpm and e-motor torque of 250Nm, the i8 will race from 0-62mph (0-100km/h) in 4.4 seconds and top out at 155mph (250km/h). However, the intelligent management of petrol and electric power means that the car emits just 46g/km of CO2 (combined), and can boast consumption figures of 2.0 l/100km. What’s more, in EV mode the i8 can provide 33 miles (53km) of electric range.
Teknikens Värld’s Hans Hedberg, a judge from Sweden, described the i8’s powertrain as “both efficient and fun to drive”, while Automobil Revue’s Tomas Hyan from the Czech Republic commented that it was “the best combination of power from the smallest cylinder capacity and an electric engine”.