Development of the Xcelsior began as a set of improvements to its predecessor, the
New Flyer Low Floor, eventually evolving into designing an entirely new bus.
Brampton Transit, in the
Greater Toronto Area, was the launch customer for the Xcelsior, receiving the first order in 2011. The Xcelsior is 10% lighter than the Low Floor, boosting fuel economy by about 7%. Its redesigned front fascia, bumpers, and roof shrouds led to better aerodynamics and driver visibility. The interior of the Xcelsior also differs significantly from the Low Floor series. By moving the fuel tank and modifying the rear suspension, seating capacity on the 40-foot model was increased from 39 to 42, with more forward-facing seats. To improve
accessibility, the floor height was lowered to with the ability to
kneel down to , and the front entry door was widened, accommodating a wider wheelchair ramp. To improve interior aesthetics, visible fasteners were eliminated and molded plastic surfaces were introduced. The utilitarian instrument panel was replaced with an automotive-style electronic dashboard. At launch, the Xcelsior was only available in a length with power from the
Cummins ISL 280 and a
Allison B400 conventional transmission or the Allison EP-40 hybrid drive.
Electric variants Development of a battery-electric variant of the Xcelsior line was announced in 2011, and a prototype was shown in 2012. Regular production began in 2014, with the first units produced for
Winnipeg Transit and the
Chicago Transit Authority. The first-generation electric Xcelsior was offered only as a 40-foot model (XE40), and used a permanent magnet traction motor built by
Siemens. In October 2017, the second-generation battery-electric Xcelsior, the Xcelsior CHARGE, was introduced, A
trolleybus version of the Xcelsior debuted in 2015 on the
Seattle trolleybus system.
King County Metro ordered both the rigid XT40 and articulated XT60 in 2013, and received the first deliveries in 2014. The
San Francisco Municipal Transportation Agency later purchased both for the
San Francisco trolleybus system, where they debuted in 2018. As of 2025, no other systems operate the trolleybus variant.
Autonomous variant New Flyer and Maryland-based Robotic Research announced a partnership in May 2019 to develop
autonomous buses. The project was funded by a million grant from the
Federal Transit Administration's Integrated Mobility Innovation Program. The prototype Xcelsior AV was unveiled in January 2021. New Flyer described the Xcelsior AV as the "first heavy-duty autonomous transit bus" in North America, and claimed that the prototype met the
SAE J3016 Level 4 of autonomy. The Xcelsior AV is battery-electric, based on the XE40 chassis, and uses Robotic Research's AutoDrive suite of sensors and AutoDrive ByWire mechanical actuators. The first three Xcelsior AV buses were scheduled to be tested in 2021 on the
CTfastrak bus rapid transit line in
Connecticut, in partnership with the
Connecticut Department of Transportation. The deployment on a BRT line, with a dedicated right-of-way, was intended to test the vehicles' ability to perform precision docking at station platforms and
platooning multiple vehicles. New Flyer rescinded the announced discontinuation of the XDE35 in May 2025. == Specifications ==