During the mid 1960’s, Mack truck was struggling for engine market share. In an attempt to distinguish themselves as an industry leader, the engineers at Mack, alongside AMBAC (formerly known as American Bosch) re-engineered turbo charger performance, and the maxidyne high torque rise concept was born. This new concept introduced a re-designed fuel system to provide ever-increasing fuel quantities as the engine was reduced. This resulted in a power band from 1200 to 2100 RPM and a 55% torque rise, which is significantly higher than the 35% torque rise of most current-day engines. The fuel system was then coupled with their new five speed maxitorque transmission, creating a vehicle with significantly less shifting as well as reduced driver fatigue. This innovative product was a huge success in the marketplace of the 1960’s and 1970’s, and only began to decline in its popularity after government emissions requirements limited its usage.