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Older Program-Wide Determinations on Bus Testing Requirements

The contents of this page do not have the force and effect of law and are not meant to bind the public in any way. This page is intended only to provide clarity to the public regarding existing requirements under the law or agency policies. Recipients and subrecipients should refer to FTA’s statutes and regulations for applicable bus testing requirements.

This page documents older determinations that applied to the entire bus industry, or to multiple manufacturers, operators, etc.  These may be partly or fully obsolete, but are retained here for reference.

2010 Freightliner MB-65 Chassis

The FTA has reviewed the new-for-2010 Freightliner MB-65 chassis and has determined that it is a variant of the MB-55 chassis, which has been tested several times at the Altoona Bus Testing Center. The FTA’s view is that the structural interface between the similar chassis frame rails and an unmodified bus body would not generate substantially different stresses compared to that of similar buses previously tested on the MB-55 chassis.  However, FTA has also determined that the MB-65 incorporates several significant differences from the MB-55 that qualify under the Bus Testing Regulation (49 CFR Part 665) as major changes and that could be expected to produce significantly different data if certain tests are repeated:

  • New front axle with 20% increased (Gross Axle Weight Rating (GAWR)
  • New front suspension
  • Upgraded rear suspension with higher ride height
  • Lowered engine
  • Revised crossmember locations, affecting driveshaft angles
  • 2010 emissions package

Based on these changes, FTA has determined that significantly different data could be expected from repeating the Maintainability, Reliability, Safety, and Structural Durability tests on a bus built on the MB-65.  FTA could also expect moderately different data from repeating the Performance, Fuel Economy, and Noise tests; these differences would not necessarily trigger additional testing on their own, but including them would be justified if a bus built on the MB-65 is already undergoing the other tests.  In addition, FTA would expect to obtain significantly different data from conducting the new Braking Performance and Emissions tests that became effective January 1, 2010 because these tests have never been performed on the MB-55. 

Consequently, one bus built on the MB-65 chassis will need to complete partial testing, including at least the Maintainability, Reliability, Safety, Structural Durability, Braking Performance, and Emissions tests, before buses built on the MB-65 may be offered to FTA recipients.  Once that bus has completed these tests, other buses that had previously satisfied Bus Testing requirements when built on the MB-55 chassis may be sold to FTA recipients using the combination of the original Bus Testing Report on that bus and a Partial Testing Report on a similar bus built on the MB-65. (Posted June 22, 2010)

Manufacturers will not be required to re-test buses solely due to the use of engines compliant with EPA 2010 emissions standards

While FTA does anticipate performance, fuel economy and potentially noise differences due to the different aftertreatment equipment and calibrations of these engines, these differences are not anticipated to be major. However, if use of a 2010 engine requires significant modifications to a vehicle itself, then additional testing might be required. In addition, data on 2010-compliant engines will become available in the normal course of testing new bus models nearly as quickly as if existing models were required to be re-tested.  Anyone wishing to obtain data on the performance and fuel economy of the 2010 engines can obtain copies of the Bus Testing Reports of buses equipped with these engines, which should begin to be available soon.  However, buses equipped with 2010 engines that are submitted for Partial Testing and which have not had the Performance, Fuel Economy, dynamic (i.e., when the powertrain is operating) Noise, and Emissions tests performed on a 2010 engine will also need to have these tests performed. (Posted October 9, 2009)

Manufacturers will not be required to re-test buses solely due to the use of engines compliant with EPA 2007 emissions standards

While FTA does anticipate some degree of performance and fuel economy differences due to the different aftertreatment equipment and calibrations of these engines, these differences are not anticipated to be major, and perhaps more importantly, no manufacturer or bus purchaser has a choice not to use 2007-compliant engines (if the 2007 engines require significant modifications to the vehicle itself, then additional testing might be required).  In addition, data on 2007-compliant engines will become available in the normal course of testing new bus models nearly as quickly as if existing models were required to be re-tested.  Anyone wishing to obtain data on the performance and fuel economy of the 2007 engines can obtain copies of the Bus Testing Reports of buses equipped with these engines, which should begin to be available soon. (Posted October 23, 2006)
 

Last updated: Tuesday, June 1, 2021