New Flyer Xcelsior

The New Flyer Xcelsior is a line of transit buses. It is made in three sizesː 35' rigid, 40' rigid, and a 60' articulated bus. New Flyer Industries started making the bus in 2008. The buses have different motors: conventional diesel, compressed natural gas (CNG), diesel-electric hybrid, hydrogen fuel cell, overhead electric wire and battery electric. 
Model codes.
For example, a New Flyer XE40 NG is a 40' (nominal) rigid Next Generation Xcelsior with battery-electric power, or an XN60 is a 60' articulated Original Generation Xcelsior with CNG power.