How do you figure that the 1688 is largerIJ We have a 1688 (ordered a 9750 STS 2 weeks ago) and my father runs a 9500. The 1688 is a 180 bushel stock tank, 9500 is 200 stock, and a tad bit more hp. Just wondering. I am keeping the 1688 for wheat and soybeans, running the STS in corn. We didnt like the AFX when we looked into it and so we went green for a chnage.