A method of operating a prime mover, the prime mover being an engine for use in a transport refrigeration system, comprising: starting the prime mover; starting the prime mover with a minimum load, the minimum load being less than a full load on the prime mover; obtaining one or more initial operation parameters of the system from one of more sensors after the prime mover is started with the minimum load, the one or more initial operation parameters indicative of a present condition of the system; retrieving one or more standard operation parameters from the system, the one or more standard operation parameters including factory-set operation parameters indicative of a standard condition of the system; comparing the one or more initial operation parameters with the one or more standard operation parameters; retrieving one or more standard operation thresholds from the system, the one or more standard operation thresholds including an up-shift point, a down-shift point, or a maximum load point, wherein the one or more standard operation thresholds can be set by an operator and are stored in a memory unit; calculating one or more optimal operation thresholds based on the one or more standard operation thresholds and the comparison of the one or more initial operation parameters with the one or more standard operation parameters, the one or more optimal operation thresholds indicative of present system and ambient conditions including an optimized up-shift point, an optimized down-shift point, or an optimized maximum load point; adding an actual load to the prime mover; and changing a prime mover speed or shedding load when the one or more optimal operation thresholds are reached. starting the prime mover; starting the prime mover with a minimum load, the minimum load being less than a full load on the prime mover; obtaining one or more initial operation parameters of the system from one of more sensors after the prime mover is started with the minimum load, the one or more initial operation parameters indicative of a present condition of the system; retrieving one or more standard operation parameters from the system, the one or more standard operation parameters including factory-set operation parameters indicative of a standard condition of the system; comparing the one or more initial operation parameters with the one or more standard operation parameters; retrieving one or more standard operation thresholds from the system, the one or more standard operation thresholds including an up-shift point, a down-shift point, or a maximum load point, wherein the one or more standard operation thresholds can be set by an operator and are stored in a memory unit; calculating one or more optimal operation thresholds based on the one or more standard operation thresholds and the comparison of the one or more initial operation parameters with the one or more standard operation parameters, the one or more optimal operation thresholds indicative of present system and ambient conditions including an optimized up-shift point, an optimized down-shift point, or an optimized maximum load point; adding an actual load to the prime mover; and changing a prime mover speed or shedding load when the one or more optimal operation thresholds are reached.