[tubesrule]

How does using a larger wattage resistor make it run cooler when the exact same wattage will be dissipated in it based on the usage? Other than the larger wattage resistor may or may not have slightly more surface area (unless you are changing to a chassis/heatsink mounted type or greatly increasing the physical size), it will run at the same temperature. The thermal resistance in free air will not be that much different and that, along with the watts dissipated is what determines the temperature.