INDIANAPOLIS — Allison Transmission’s 2019 hybrid-electric propulsion system, paired with Cummins engines, has received certification from California’s air quality agency.

Allison Transmission Holdings Inc. and Cummins Inc. were granted certification from the California Air Resources Board (CARB) for model year 2019 Allison Hybrid 40/50 Electric Propulsion (H 40/50 EP) system paired with the Cummins B6.7 and L9 diesel-electric hybrid engines used in transit buses and motorcoaches.

“We appreciate CARB’s continued renewal,” said Barbara Chance, director of mobile source regulatory compliance for Allison Transmission. “Allison was the first electric hybrid propulsion system to be certified in California for transit buses and coaches. We look forward to continuing our work with CARB.”

The Allison H 40/50 EP has reportedly been proven to improve fuel economy up to 25% over similar diesel buses, according to Allison Transmission, and its regenerative braking capability can significantly extend the brake change interval by as much as 350%.

“Cummins is pleased the Allison electric hybrid propulsion system has received 2019 CARB certification,” said Brian Wilson, general manager of global bus business at Cummins. “We believe the latest Cummins and Allison clean diesel power system will provide our bus customers an even more reliable and environmentally-friendly powertrain to help them be as successful as possible. For 2019, our latest generation of B6.7 and L9 engines are enhanced with improved fuel economy and improved uptime, reducing overall costs for customers.”

The B6.7 diesel-electric hybrid engine is rated at 280 horsepower (209kW) while the L9 diesel-electric hybrid engine is rated at 330 horsepower (246kW) for the transit bus market.

Originally issued by the CARB in 2014, the dual executive order is required to be reviewed for renewed eligibility on a model year basis, according to Allison Transmission.