On-Road Test and Evaluation of Emissions and Fuel Economy of the Hybrid Electric Bus

A test evaluation method for the emissions and fuel economy of heavy duty hybrid electric vehicles (HD-HEVs) was developed, which was implemented on a standard track with an integrated onboard measurement system (IOMS). One home-made hybrid electric bus (HEB) and a conventional diesel bus were tested with the presented procedure. The track test adopted a city-bus cycle which was developed and formed through bus driving modes collection in several typical megacities of China. The feasibility and effectiveness of the presented method and procedure were validated in the track tests: the test cycle can be well followed with a high unity more than 0.97 and a R2 more than 0.99 by a driver after only a few hours training, and the on-board measurement system performed with a good reliability. Results of the track tests shows that the tested HEB possesses 39% higher fuel economy than (or achieves 28% fuel saving compared with) its conventional counterpart, and the HEB’s emissions of HC, CO, NOx, CO₂ and PM are respectively 26.8%, 28.9%, 15.8%, 27% and 37.3% less than those of the reference diesel bus.