Low engine speed concept Fendt iD. Those who drive a Fendt 1000 Vario no longer have to bother themselves with the best engine speed ranges. They are always automatically ideal. The Fendt 1000 Vario always runs in the maximum torque range for the lowest specific fuel consumption, which means that high power is already delivered at low engine speeds. “High torque, low engine speed” is the principle under which all vehicle components, such as the engine, transmission, fan, hydraulics and all consumers, were designed for ideal speeds.