Abstract: The present invention is a method for obtaining an inferred soak time suitable for inferring exhaust system and other temperatures with sufficient accuracy to permit control of at least one feature of an internal combustion engine to be based thereon. In this way, soak time strategy can be inexpensively incorporated into an engine control system not based on soak time or soak timer hardware can be replaced in control systems with soak time strategy. The temperature of the engine and of the charging air supplied to the engine are measured at the time the engine is turned off and when the engine is restarted. The measured temperature of the engine and of the charging air at the time the engine is turned off is stored in a computer memory. The inferred soak time is obtained using the measured temperature of the engine and of the charging air stored at the time the engine is turned off and measured at the time the engine is restarted.