LAS VEGAS, Nev. — Cummins has announced its 2013 engine line for the vocational market, claiming customers will see up to 2% better fuel economy than with 2012 models.

The fuel economy improvements are attributed to improvements in subsystem components, including the XPI fuel system, VGT turbo, Cummins aftertreatment system with DPF and SCR, all powered by a single engine control module resulting in improved combustion efficiency, performance and reliability, the company says. There are no major hardware changes in Cummins’ 2013 engine line.

The 2013 engines are certified to the impending GHG14 standard, which comes into effect next year.

“Cummins remains focused on delivering engines with better fuel economy, reliability and durability with lower operating costs. Cummins and Cummins Westport offer customers a range of horsepower and torque ratings with both clean diesel and natural gas engines to meet the needs of our vocational customers,” said Jeff Jones, Cummins vice-president, North American engine business and market communications.

Cummins 2013 vocational engine line includes the ISX12, with 310-425 hp, and SmartTorque ratings that deliver an extra 200 lb.-ft. of torque in the top two gears and vocational ratings that provide additional torque in the lower gears. Options include front- and rear-mounted power take-offs.

The ISL9, with ratings of 260-380 hp, features replaceable wet liners, roller followers, by-pass oil filtration and targeted piston cooling. Cummins says the engine is suitable for tough work environments and boasts the highest power density of any engine in its class.

Also available are natural gas versions of both engines, the ISL G and ISX12 G. They are equipped with Cummins Westport’s spark-ignited combustion technology with stoichiometric cooled EGR and maintenance-free three-way catalyst.

The ISL G is available with 250-320 hp while the ISX12 G can be had with 320-400 hp. The ISX12 G can be ordered with an automatic or manual transmission and engine braking, making it an ideal heavy-duty natural gas engine, Cummins announced. It will enter limited production in April. Both natural gas engines can run off either compressed or liquefied natural gas.