[ry0972]

Same head, yes. We've kept the same head through three machines so far. The 8120 had no increased capacity whatsoever over the 7010 we had before (same speed, same throughput), but burned more fuel, which was a huge disappointment to us. I know of others that have had similar experiences in this area. In our conditions more hp often means you just lose grain faster while burning more fuel. There are many limiting factors other than HP. We now run a 7230 and 7240. Class 8 would be a waste of money for us. However the 7240 has about as much hp as the 8120 had, but seems to have a more efficient engine as it's easier on fuel than the 8120 was.

Off topic, but all of this leads me to call BS on the guys that claim you have to keep the combine full for it to work best. So you have a class 7, 8 and 9 machine, all identical in every way except horsepower. A "full" 7120 could be a 9120 at 70% engine load. So the 9120 would not be "full" but the 7120 would be doing the same exact material through-put.

I agree with your last statement.
As to the first I know a few guys that run CIH 7XX0, 8XX0 and 9XX0 machines together and they claim the 9XX0 machines burn very little more fuel if run side by side with same headers.
But when it gets tough and/or you start putting through lots of straw and making use of the extra HP in the bigger engine fuel use rises A LOT.
I do NOT understand how more HP alone can really make a combine "BIGGER" as to harvesting/threshing/separating ability??
This year there will be a lot of class 9/10 machines harvesting crop that a class 2 combine could run through with ease!!!!
Does anyone have an 80ft Honey Bee draper header laying around I could borrow? LOL
I would only need it a day or 2!!