The Trane XV80 and XC80 gas furnaces are Trane’s two stage, variable speed systems. These two furnaces have all of the same benefits of the XL80 but add more electrically efficient fan motors, even quieter operation, and feature rich software on the XC80. Combined with the advanced ComfortLinkâ„¢ II thermostat, the XC80 provides a number of features for those homeowners wanting the finest HVAC technology offers today.