Houndstooth,
From looking at the Nebraska Test Site, it seems like the fuel usage for tractors range from about 0.1 gal/hr/hp to 0.05 gal/hr/hp. I think at full speed, the base HST tractor consumes about 7 hp just sitting. A cab(air conditioner, fan, etc) consumes ~5 hp. This would lead to a consumption of ~1.2 g/hr (assuming the NH is on the low end of efficiency) just sitting there at full speed. Fully loaded, a 45 hp tractor would consume 3-4 g/hr.
The difference in usage compared to your old tractor is likely the things that makes it more enjoyable to drive, but consume HP. Your usage of ~2 gph seems reasonable for a 10 hp pto/axle load.
A friend had an old 283(I think) chevy pickup with a 5 speed. He would get 20-25 mpg on trips to colorado. However, he could only do 70 mph, it was small, and had a week air conditioner.
He bought a 4wd dodge ram pickup(that had twice the frontal area, weighed 50% more, was an automatic, and had the biggest V8), and drove it to colorado, and got 12-15 mpg. He drove 80, and had the air on high. He concluded that Dodge pickups had awful mileage. He was right. He bought a much smaller stick chevy, and gets 20+, and is happy.
I have a smaller dodge(1500), and am happy, too. (It truly is less efficient than an equivelant Chevy, but not that much less efficient. I don't know about Ford).
Chris
