A car transmission's overdrive function applies just enough engine energy to help maintain the desired speed. The engine is not running at its top speed, but the car uses less fuel per mile. Engineers have applied that same engineering principle to a standard feature of Putzmeister boom pumps that are mounted on Mack chassis.
Dubbed the Econo-Gear system, the patent-pending system allows an operator to choose a unique gear ratio that outputs the proper pumping pressure to deliver concrete at the same rate, but it allows the engine to run at less than maximum output.
Field studies have shown that pump operators can expect about a 5 percent savings in fuel consumption in full-load pumping applications when using the system. For a typical slab on grade or tilt-up panel pour, some operators have documented up to a 25 percent reduction in fuel consumption.
Operating the pump in the overdrive gear has other advantages: a lower engine noise level and less engine wear.