Abstract: Apparatus for automatically controlling the ready-to-drive condition while maintaining ready-to-start temperature of a single or multiple gas, gas-diesel or diesel engine in automobile uses a electronic circuit linked to various sensors including a temperature sensor, a vibration sensor, and a motion sensor. Signals generated by the temperature sensor are used for auto-reset and to turn the engine on and off based on predetermined maximum and minimum temperature. For multiple engines, sensor can be used to actuate a secondary engine if the primary engine reaches a predetermined maximum temperature and switch back to the primary engine when the engine temperature drops to a predetermined low temperature. For multiple engines, the vibration sensor output determines when control is switched from the primary engine to the secondary engine or vice versa, and also determines the engine cranking time for both multiple and single engines.