Cummins Power Generation says its two new diesel G-drive engines are certified to meet EPA Tier 4 Final emissions regulations for nitrogen oxides (NOx) and particulate matter (PM or soot) without the use of a a diesel particulate filter (DPF).
Instead, the new engines employ a combination of in-cylinder combustion improvements, exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) exhaust aftertreatment. These new engines are suitable for powering generators from 150 to 300 kVA.
The Tier 4 Final G-drive engines, available Q2 2014, will be the QSB7 and QSL9. The QSB7 is rated at either 240 or 315 horsepower and designed to power generator sets with standby ratings of 150 kVA to 220 kVA. Available at the end of Q2 2014, the QSL9 will be rated at 433 horsepower and designed to power generator sets rated at 300 kVA.
George Iarca, regional manager for G-drive, Cummins Power Generation, says because the engines don’t need a DPF, they offer reduced maintenance costs and a 4 percent better fuel efficiency than previous Tier 3 engines.
The Tier 4 Final G-drive engine packages will also include diesel exhaust fluid (DEF) dosing and supply modules that control the dispensing of DEF into the SCR to cut emissions of NOx. Equipment manufacturers will need to supply the DEF tank and fluid-handling accessories, as these items tend to be sized to complement fuel tank size and intended runtimes for the final generator set package. The normal consumption of DEF is about 4 percent of fuel consumption, the company says.