Program-Wide Determinations on Bus Testing Requirements

FTA has issued several determinations related to requirements for Bus Testing that are of interest to the entire transit bus industry.  They are presented here to maximize their availability and consistency in application.  If there is a date on which the policy becomes effective, then it will be explicitly specified in the text below; otherwise, the dates shown are simply the dates the policy was posted on this website.

• 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)

• Clarification regarding unmodified mass-produced vans.  While unmodified mass-produced vans are categorically exempted from testing by the Bus Testing Regulation, this exemption historically assumed that unmodified mass-produced vans would only be offered in the 4-year, 100,000-mile service life category.  FTA wishes to clarify that unmodified mass-produced vans are categorically exempted from testing by the Bus Testing Regulation only in the 4-year, 100,000-mile service life category; unmodified mass-produced vans offered in the 5-year, 150,000-mile (or higher) service life category are subject to testing. (posted January 30, 2007)

• 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)
   

• Changing the primary structural material of a bus from mild steel to stainless steel will generally be considered a major change, and will generally require partial testing including the structure-related tests.  FTA considers changing from mild steel to stainless steel to be a “major change in chassis design” as defined in the Bus Testing Regulation that triggers additional testing.  Compared to mild steels, stainless steels have different physical properties, different microstructure, and different (generally more stringent) manufacturing requirements.  Years ago, FTA allowed a bus model that had been tested with a mild steel chassis to be sold without additional testing with a stainless steel chassis; when the stainless steel model entered service, it experienced numerous structural problems. (posted May 26, 2006)