New Flyer Xcelsior
New Flyer XD40 (diesel)
Overview
Manufacturer	New Flyer
Production	2008–present
Body and chassis
Class	Transit bus
Body style	Monocoque stressed-skin
Layout	Rear-engine or rear-motor, rear-wheel-drive Center- and rear-motors, four-wheel-drive (XE60 and XHE60, optional on XDE60)
Doors	2 doors (35-foot) 2 or 3 doors (40-foot) 2, 3 or 5 doors (60-foot)
Floor type	Low-floor
Powertrain
Engine	Diesel: Cummins L9 Hybrid: Cummins B6.7 (35- & 40-foot) or L9 (60-foot) CNG: Cummins-Westport L9N
Electric motor	Battery Electric: Siemens ELFA 3 (plus ZF AVE130 on 60-foot) Hybrid: Allison H 40 (35- & 40-foot), H 50 (60-foot), BAE HDS200 (35- & 40-foot) or HDS300 (60-foot) Hydrogen: Siemens ELFA 2 (plus ZF AVE130 on 60-foot) Trolley: Kiepe Electric
Transmission	Allison B 400 (35- & 40-foot), B 500 (60-foot), Voith or ZF
Dimensions
Wheelbase	226.75 in (5.76 m) (35-foot) 283.75 in (7.21 m) (40-foot) Front: 229 in (5.82 m) / Rear: 293 in (7.44 m) (60-foot)
Length	over bumpers: 36 ft 3 in (11.0 m) (35-foot) 41 ft (12.5 m) (40-foot) 60 ft 10 in (18.5 m) (60-foot)
Width	102 in (2.59 m)
Height	10 ft 6 in (3.20 m) (diesel) 11 ft 1 in (3.38 m) (all others)
Curb weight	24,500–29,300 lb (11,100–13,300 kg) (35-foot) 26,000–30,500 lb (11,800–13,800 kg) (40-foot) 39,000–45,500 lb (17,700–20,600 kg) (60-foot)
Chronology
Predecessor	New Flyer Low Floor

The New Flyer Xcelsior is a line of transit buses available in 35-foot rigid, 40-foot rigid, and 60-foot articulated nominal lengths manufactured by New Flyer Industries since 2008. In addition to the different available lengths, the buses are sold with a variety of propulsion systems: conventional diesel, compressed natural gas (CNG), diesel-electric hybrid, hydrogen fuel cell, overhead electric wire and battery electric. A future autonomous bus variant was announced in January 2021.

For example, a New Flyer XE40 CHARGE NG is a 40-foot (nominal) rigid Next Generation Xcelsior with battery-electric power, or an XN60 is a 60-foot articulated Original Generation Xcelsior with CNG power. All power sources have 40- and 60-foot models, but not all power sources have 35-foot models: XHE35s (hydrogen-powered) and XT35s (trolleybus) do not exist.

The Xcelsior was introduced October 2008 APTA Expo held in San Diego. The Xcelsior started off as a set of improvements to the company's prior product, the New Flyer Low Floor, but over the development process the company said it ended up designing a new bus. Compared to the Low Floor, the Xcelsior was 10% lighter, boosting fuel economy by about 7%.^[1]

The bus was also designed to allow a much larger cooling system and the addition of a SCR system, both required to meet the more stringent EPA mandates that were coming in 2010. To accommodate the change, the Thermo King air conditioning system was moved from the rear of the bus to a roof mount location over the front axle. New Flyer found that the move improved the weight balance of the bus, and when combined with enhanced insulation, contributed to the vehicle running quieter.^[2]

The interior of the bus was also modified. By moving the fuel tank and modifying the rear suspension, seating capacity was increased from 39 to 42 (on the 40-foot model), with more forward-facing seats. To improve accessibility, the floor height was lowered to 14 inches (360 mm) with the ability to kneel down to 10 inches (250 mm), and the front entry door was widened, allowing 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.^[2]

The bus also had a redesigned front face, bumpers, and roof shrouds that also offered better aerodynamics and the front improved visibility for the driver.^[2]

At launch, the Xcelsior was only available in a 40-foot (12 m) length with power from the Cummins ISL 280 and a Allison B400 conventional transmission or the Allison EP-40 hybrid drive. Brampton Transit, serving Brampton, Ontario, was the first agency to order the Xcelsior.^[2]

The first trolleybus version of the Xcelsior was an XT40 built in 2014 for the Seattle trolleybus system, operated by King County Metro,^[3] the first unit of an order placed in 2013.^[4] King County Metro also purchased the XT60 (articulated trolleybus),^[4] and both XT40s and XT60s were subsequently purchased by the San Francisco Municipal Railway, for the San Francisco trolleybus system.^[5]

Beginning with the 2026 model year, the XDE60 will be discontinued as New Flyer was unable to find a powertrain compliant with new regulations taking effect around that time. With the 2027 model year, the XDE35 and XN35 will both be discontinued due projected low demand. ^[6]

The first Xcelsior battery electric buses (XE40) were built in 2014 and delivered to the Chicago Transit Authority and Winnipeg Transit.^[7] Massachusetts Bay Transportation Authority was the lead agency for the XE60, ordered in January 2019^[8] and placed into service on July 31, 2019.^[9] The Toronto Transit Commission operates 25 XE40 buses.

The first battery electric Xcelsior buses were a powertrain option within the regular Xcelsior line; development was announced in 2011, a prototype was shown in 2012, and regular production began in 2014.^[10] The original battery electric Xcelsior bus, offered as an XE40, used a permanent magnet traction motor built by Siemens.^[11] In October 2017, the Xcelsior CHARGE sub-line was introduced.^[10]

The Xcelsior CHARGE variant (XEnn) uses the Siemens ELFA2 electric drive system with different options for battery capacity, depending on the charging speed and range required.^[12] The traction motor used has an output of either 210 or 280 hp (213 or 284 PS; 157 or 209 kW) and 1,033 or 1,475 lb⋅ft (1,401 or 2,000 N⋅m; 143 or 204 kg⋅m).^[13] Batteries are supplied by XALT Energy^[14] or A123 Systems (XE60 long-range models and XHEnn fuel cell models).^[13] On-route rapid charging is provided through an overhead pantograph designed to be interoperable with the SAE J3105 standard supplying 300–450 kW. Shop or depot charging may be performed using SAE J3068 and J1772 connectors supplying up to 150 kW.^[13][7]

At Altoona, the as-tested empty weight of an XE40 was measured at 32,770 lb (14,860 kg) with a capacity of 76 (38 seated passengers + 37 standing passengers + 1 driver) for a total GVW of 43,550 lb (19,750 kg). It was equipped with 4 XALT Xsyst 7 (7 kWh) batteries and a SPHEROS fuel-fired heater. When accelerating from a constant speed, the bus emitted an average maximum noise level of 66.1 dB(A),^[15] considerably lower than the average maximum noise level of 70.4 dB(A) measured from a conventionally-powered XD40.^[16]

The articulated XE60 adds a second driven axle, using the ZF AxTrax AVE^[17] on the middle axle.^[10] The AxTrax AVE (formerly known as the AVE 130)^{[dead link‍][18]} uses two electric motors (one per wheel), each with a maximum continuous/peak output of 160 / 340 hp (162 / 345 PS; 119 / 254 kW) and maximum continuous/peak torque of 6,000 / 16,200 lb⋅ft (8,135 / 21,964 N⋅m; 830 / 2,240 kg⋅m).^[19] Each motor is an asynchronous three-phase AC motor operating on 650 VDC with an input current of 250 (continuous) to 340 (peak) amps, using a single-speed reduction gear ratio of 22.66:1. The complete axle assembly weighs 2,760 lb (1,250 kg)^[20]

The as-tested empty weight of an XE60 was 52,070 lb (23,620 kg) with a capacity of 120 (50 seated passengers + 69 standing passengers + 1 driver) for a total GVW of 70,170 lb (31,830 kg).^[19] Compared to the diesel-powered equivalent XD60, the XE60 is heavier (XD60 GVW is 58,600 lb (26,600 kg)) and holds slightly fewer people (XD60 capacity is 123 people: 49 seated, 73 standing, 1 driver).^[21] Depending on the driving route/style, the XE60 tested at Altoona had a predicted range of 145 to 246 miles (233 to 396 km).^[19]

The MBTA and NYMTA were the first to order the XE60, with the former ordering 5 and the latter ordering 15.

Xcelsior CHARGE NG is New Flyer's next generation battery electric, zero-emission bus. It is lighter, simpler and has longer range with better energy recovery. It has a capacity of 32-61 passengers with 2 wheelchair locations. It is available in 35-, 40-, and 60-foot configurations. It has a Siemens ELFA3 traction motor, Lithium Manganese Cobalt (NMC) batteries, and electric roof-mounted HVAC(s).^[22]

The CHARGE model can be equipped with a hydrogen fuel cell (model code XHE), which acts as an on-board charger to extend range.^[23] Earlier New Flyer fuel cell buses were based on the preceding Low Floor chassis, designated H40LFR, and integrated by an outside vendor. In 2016, New Flyer received an order for 25 XHE40 buses under the California Air Resources Board Air Quality Improvement Program (AQIP).^[13] The XHE40 uses a MAN SE model 1350 rear axle with a traction motor from Siemens; like the XE60, the XHE60 also uses a MAN 1350 rear axle as a pusher, but adds a ZF AxTrax AVE middle axle as a puller for traction-challenged conditions.^[24]

An XHE60 tested at Altoona weighed 49,890 lb (22,630 kg) empty; with a total capacity of 132 (1 driver, 50 seated, 81 standing), the estimated GVW was 69,750 lb (31,640 kg). The fuel cell was a Ballard HD85 with an 85 kW output.^[24]

Development of the electric fuel cell buses is centered in California, with AC Transit serving as the lead agency for one XHE60, and SunLine Transit Agency, AC Transit, and Orange County Transportation Authority testing several variants of XHE40.^[7]

New Flyer and Robotic Research announced a partnership in May 2019 to develop automated bus technology.^[25] In January 2021, New Flyer introduced the Xcelsior AV, New Flyer's first ever autonomous bus.^[26] New Flyer claims the AV meets the SAE J3016 Level 4 of autonomy. The AV is based on the XE40 chassis, and uses Robotic Research's AutoDrive suite of sensors and AutoDrive ByWire mechanical actuators.^[27] Project management was performed by The Center for Transportation and Environment (CTE) with support from the Federal Transit Administration, who provided a US$2 million grant under the Integrated Mobility Innovation Program.^[28]

The first three Xcelsior AV buses are scheduled to be tested by CTtransit in 2021 on the CTfastrak bus rapid transit (BRT) line, over a dedicated right-of-way 9 miles (14 km) long, connecting New Britain and Hartford, Connecticut. The deployment on a BRT line is anticipated to test the vehicles' ability to perform precision docking at station platforms and platooning multiple vehicles.^[28]

• 
  XE60, NYMTA
• 
  XD60, NYMTA
• 
  XE40, WMATA Metrobus
• 
  XE40, TriMet
• 
  XD35, Greater Bridgeport Transit
• 
  XDE40, SEPTA
• 
  XDE60, MBTA Silver Line
• 
  XHE40, AC Transit
• 
  XT40, King County Metro
• 
  XT60, SF Muni
• 
  XN40, NYMTA
• 
  Blank XD40 in Montreal
• 
  XD60, Winnipeg Transit
• 
  XN60, Metro Transit (Omaha)
• 
  XDE35, Suffolk County Transit
• 
  XE60, Spokane Transit
• 
  XD40 interior, DART
• 
  XE60 interior, Spokane Transit
• 
  XE40 interior, TriMet

• BYD K9
• ENC Axess
• Gillig Low Floor
• Nova Bus LFS
• Proterra ZX5

Wikimedia Commons has media related to New Flyer Xcelsior.

• "xcelsior®" (PDF). New Flyer. September 2017. Retrieved December 10, 2018.
• Xcelsior NG: https://www.newflyer.com/bus/xcelsior-charge-ng/

• Xcelsior family overview
• Xcelsior AV
• Xcelsior CHARGE H2
• Xcelsior CHARGE NG
• Xcelsior Clean Diesel
• Xcelsior CNG
• Xcelsior Hybrid-Electric
• Xcelsior Trolley-Electric