I am looking for more information on the following furnaces (AFUE and other specs):
York P4USD12N08001A furnace
Lennox G1203-82 furnace
The York is mine, and the Lennox is my neighbor's, and we are thinking of replacing it with new 90%+ efficient furnaces, to lower gas bills. Any comments about these old furnaces, and the pros and cons of changing them (reliability of new furnaces, etc) are welcome. They are well maintained and not giving any problems. It's the $$$ for gas bills that's driving us to consider newer more efficient furnaces. We live just north of Cincinnati, and have been getting some cold winters the past few years.
Thanks for your advice.