A transmission hot idle engine is a type of engine that is designed to operate at high temperatures while idling. This type of engine is typically used in vehicles that are frequently used in stop-and-go traffic, such as taxis and buses.
The main benefit of a transmission hot idle engine is that it helps to reduce the amount of fuel that is consumed while idling. This is because the engine is able to operate at a lower RPM when it is hot, which reduces the amount of fuel that is needed to keep the engine running.