The 114SD NG is designed and built for optimized uptime and productivity, even in the most rugged conditions. Powered by the spark-ignited, dedicated natural gas Cummins Westport ISL G 8.9 liter engine, the 114SD NG is designed for efficiency. The heavy-duty 114SD also features an Allison 3000 RDS automatic transmission, ideal for alternative fuel vehicles. This transmission features patented torque-converter technology that results in improved starting power at the launch of the truck and full-power shifts.