Carrier 58HDV Furnace
That's odd ... there seem to be some discrepancies in the manuals I found, and some of them seem to indicate that the 58HDV line is not multi-stage heat, while others do.
Do you have the exact model number for the furnace? Also, does the nameplate on the furnace list both high and low stage heat ratings?
If you DO have the furnace indicated in your link, then that IS a multistage furnace, and you would perhaps benefit from a multistage thermostat - although some furnaces control this outside of the thermostat (i.e. they ramp up from low to high heat based on a time schedule).