Introduced in 1998 as a 14.9 litre diesel engine, the Cummins ISX was originally marketed for the heavy-duty truck market. For 2010, coinciding with the EPA 2010 emissions regulations, a 14.9 and 11.9 litre version is avialable; known as the ISX15 and ISX11.9 respectively. Both models are intended to be available for the motorcoach market, replacing the Cummins ISM. The ISX11.9 was renamed the ISX12 in 2012 coincident with electronic recalibration.
The engine originally featured double overhead camshafts. One drove the high-pressure fuel injection and the second operated the intake and exhaust valves, with integration of an engine brake avaiable. The 2010 ISX features a signle overhead camshaft as the XPI fuel system added for 2010 eliminates the need for a second camshaft. The ISX also features a variable Geometry turbocharger and cooled EGR. Improved EGR is featured for 2010, lowering combustion temperatures for reduced emissions and optimized fuel economy. Cummins integrated electronic controls (Electronic Control Module (ECM)) controls the workings of the engine from air intake to exhaust aftertreatment.
Cummins intended for the ISX to meet EPA 2010 regulation without using selective catalytic reduction (SCR), but In late 2008, Cummins announced they will use SCR for all their engines except for the ISM, which was replaced by the ISX11.9. The reasoning for the change was new developements in the technology with the use of copper zeolite. The ISX15 was awarded EPA 2010 certification on January 8, 2010, while the ISX11.9 was awarded EPA 2010 certification on July 20, 2010.
- ↑ Cummins ISX. Diesel Power. Retrieved on 18 June 2009
- ↑ Berg, Tom (27 January 2012). Cummins Retunes ISX11.9 for Better Economy, Renames It ISX12. Power Systems Research. retrieved on 23 April 2012.
- ↑ Carretta, Justin (13 August 2008). Cummins to use SCR across the board in 2010. FleetOwner. Retrieved on 14 June 2009