to stir up a hornet's nest.

Yes, the fuel costs something. $2.50 fuel and I'm getting somewhere a bit over 3 acres with a gallon. Remember; the disk is not working deep. Just enough to shave the weed roots and chop them up a bit. Doesn't take anywhere the same amount of fuel that deep tillage with a heavy disk can take. As Cougar mentioned above; conservation of moisture is usually a good idea here so all tillage deeper than a couple inches is avoided on my farm. That's one of the reasons I'm such a stickler for leaving fields level and using tools that follow the contour of the ground as closely as I can muster. If you leave ridges and gullies in your fields, then you need to work some parts deeper than necessary, drying the soil too much and also freeing more OM into the atmosphere instead of leaving it in the soil where it does you and your crops some good.

As far as wear and tear on belts and tractor; The tractor just turned 15 years old, the belts have more than half their lug depth left, the engine is barely broke in and the running gear of the tractor is no where near half way worn out. The tractor has been relegated to the 'choring around tractor' so will not see the same hours in the next 15 years that it has in the first 15. Whether I use it or not, it will have pretty much the same value and utility 20 years down the road, so again, you tell me what my per hour costs for running the tractor are. I never intend to sell it and taxes and insurance is the same whether I put 20 hours / year or 200 on it.