Case Study: Federal Transit Administration achieves 50% fuel savings and lowest life-cycle cost with Altair ProductDesign's series hydraulic hybrid bus

Developing the World’s First Series Hydraulic Hybrid Bus

The Federal Transit Administration needed a more fuel-efficient, lower-emission, and lower life‑cycle‑cost transit bus to reduce operating subsidies and improve city transit systems. Altair ProductDesign (Altair) led the BUSolutions effort to meet that challenge, targeting development of the world’s first series hydraulic hybrid bus and a platform that could be maintained without changing existing transit infrastructure.

Altair ProductDesign used a simulation‑driven, optimization approach—optimizing an aluminum frame, lightweight fittings, low‑friction tires and a series hydraulic hybrid propulsion system that captures braking energy as pressurized fluid. The Altair solution delivered twice the fuel efficiency of conventional diesel buses, 30% better fuel economy than current diesel‑electric buses, the lowest life‑cycle cost of any hybrid or diesel bus, and a projected savings of $25,000 per vehicle per year.

Federal Transit Administration