Available in 4- and 6-cylinder platforms, Tier 3-compliant QSB engines are rated from 110 to 275 hp. Sculpted blocks and rear gear trains help reduce noise levels. A High-Pressure Common-Rail fuel system can generate to 1,600 bar injection pressures for refined and rapid power delivery, reduced noise and improved cold start. No longer dependent on engine speed, load conditions or fueling capability, injection pressure can be constant at all speeds. The engines are backed by the QuickServe Guarantee program.