Here is how the new naming convention would be used on combines:
For combines, model numbers have four positions. The first is a letter indicating the type of combine - T for tangential-tine separation or S for single-tine separation, for example. The second position indicates the combine's capability level and size in relation to other John Deere combines: 6 for example, means a high-spec model with a wide body. The third position indicates relative power, 7, for example, indicating a 373-hp machine. The fourth position is reserved for future use.
Thus, a T670 (spoken as tee-six-seventy) designates a tangential-tine separation machine with a relatively high capability level and 373 hp.