Cummins offers four different engines that are widely used in school bus fleets. Two are clean diesels – the ISB6.7 and the ISL9, which replaces the ISC8.3. The others are our natural gas Cummins Westport ISL G and ISB6.7 G.

All of these engines help you reduce fuel expenses as well as greenhouse gases (GHG). Cummins is boosting the industry-leading fuel economy of our 2013 ISB6.7 and ISL9 engines up to 2% higher versus 2010 models. How? The addition of an air intake throttle makes our EGR system more efficient, while the VGT™ Turbocharger on the ISL9 has been modified for greater efficiency as well. The reduction in parasitic losses increases fuel economy and lowers operating costs. The Cummins Westport ISL G and ISB6.7 G take advantage of an abundance of domestically produced natural gas, which results in lower fuel prices.

The ISB6.7, ISL9, ISL G and ISB6.7 G will meet 2014 Environmental Protection Agency (EPA) and United States Department of Transportation (DOT) regulations for fuel economy and greenhouse gas reduction, a year ahead of schedule. We have done so without major hardware changes – so you can expect the same proven reliability and durability as current model engines.