The 4-cylinder QSB4.5 for Tier 4 Final is more powerful and responsive than ever before, delivering up to 173 hp (129 kW), with a peak torque of 520 lb-ft (705 N•m), a 12 percent increase over that of the previous Tier 4 Interim engine. The Tier 4 Final QSB4.5 shares a similar Cummins VGT Turbocharger, an HPCR fuel system and an ECM with the Cummins QSB6.7 engine. It is not surprising that the QSB4.5’s power output is comparable in performance to that of many 6-cylinder engines below 174 hp (130 kW), from a much smaller and lighter package.
Certification Level Tier 4 Final / Stage IV
Power 121 – 173 hp / 90 – 129 kW
Torque 347 – 520 lb-ft / 470 – 705 N•m