The actual combine class size determinate has been settled on, by the industry manufacturers, as Horsepower. The classification is currently being implemented by AEM (www.aem.org),which is the only governing body (made up of industry reps.) in the industry able to enact such classifications. Attmepts, however, had been made in the past by ASAE. It has always been assumed that there must be at least three models to determine a class. Because combine classification is only an assumption, that makes the assumption that three combines determine a class size void. By using horsepower as the determining factor, combine manufacturers will become more innovative in order to achieve greater levels of productivty. Size will no longer play as large a role in combine performance and productivity as much as the technology used will. Combine class sizes and models. Remember, its horsepower, not machine size! Class 5 (215 - 270hp): JD 9550 (CWS and STS); the discontinued CIH 2366; lexion 450 Class 6 (270 - 320hp): JD 9660 (CWS, STS** and CTS); AGCO Gleaner R65 and C62, Massey 9690* and 8680, Challenger 660*; CIH 2388; lexion 460 and 460R; NH CR940 and CX840 Class 7 (320 - 375hp): JD 9760STS**; AGCO Gleaner R75, Massey 9790* and Challenger 670*; lexion 470R_475R; NH CR960, CR970 (because the 970's horsepower doesn't qualify it for class eight, but I am sure NH will bump it five or six hp to qualify it for later this year),CX880 Class 8 (-375hp): JD 9860STS**; lexion 480R_485R; CIH 8010 * = Same AGCO model (Massey and Challenger rotary combines) ** = Same size threshing_separating_cleaning systems for class 6-8 STS models, just different engine hp ratings. Except for the NH CR970, all other CR models are the same size (physical and system),as are the CX model walker combines, just different horsepower ratings. As you can see by the use of similar size machines, size isn;t making the class size anylonger (assumed).