Furnace Efficiency Ratings by the Gas Appliance Manufacturer's Association
Gas Appliance Manufacturer's Association, or GAMA, has stringent requirements of manufacturer's testing procedures. Government agencies and the heating industry respect GAMA as the authority on all types of commercial and residential gas fired equipment . Visit their website at
A tip on using GAMA's Energy Efficiency ratings page:
You only need to fill in a couple of keywords in the main search field.
To look for Gas Appliance Manufacturers Association (GAMA) ratings for our Amana and Armstrong furnaces:

Go to the GAMA Consumers' Directory of Certified Efficiency Ratings page:

The top center list is the manufacturers list. Click the list arrow on the drop down list and choose Residential Furnaces. Click the "Select Appliance" button, it will take you to the next page. Click the list arrow on the drop down list and select the manufacturer.

The second line down left side has a place to enter the model number. Enter the first few letters and/or numbers of the model number. Usually just the first 3 or 4 letters/numbers are best, if you type the entire model number in it may not find it due to a dash or dot missing or present.

Click the "Search Database" button.

Effiency is rated as AFUE* in %.
*AFUE means Annual Fuel Utilization Efficiency.Helpful Hints on Creating Queries

1. It is often not necessary to complete all fields. Entering data in multiple fields will restrict the results.
2. The use of wildcards (i.e. '*', '?') are not necessary since they are built-in simply by entering any portion of a model number (i.e. for model number ABC16XPT, entering ABC16, XPT, 16 or just BC will pull up the model you are seeking).

This method will work for any other furnace brand and model. It's your money for energy you will spend over the lifetime of your next furnace! The higher the effiency - the more heat stays in your house and the more money stays in your wallet!
 
Notes on Furnace Ratings

The "fleet efficiency" or "furnace rating" of a particular furnace brand indicates nothing about furnace quality or furnace durability. In addition, although the fleet efficiency of one brand might exceed that of another, this does not necessarily indicate that any particular model of furnace marketed under the first brand is more efficient than any particular model of furnace marketed under the second brand.

To determine whether one model is more efficient than another, simple compare the AFUE of the two models.