Trane’s S9V2 and XC95m gas furnaces are Trane’s variable speed, high efficiency gas furnaces. Their multi-stage operation reduces furnace noise, encourages room to room temperature balancing, reduces temperature swings between heating cycles, provides cleaner indoor air, and has fewer on/offs to help preserve the life of the unit. In addition, these models offer more electrically efficient fan motors as well as feature rich software on the XC95m circuit board. When paired with Trane’s Comfort Link II thermostat, the XC95m you will have features you would otherwise not have, such as system diagnostic display on the thermostat (this will alert you of any problems with the furnace), WiFi, and so on. If you are interested in having the best technology found in a gas furnace today, this is the model of choice.