How much gas do they use, the cost per day from average usage? I just spent the whole day clearing off useless overburden soil from a 20 square foot section and am completely exhausted. Even a small dozer like that could do a better job than I can.
You make a very valid point. When I use my log loader as an upside down woodsplitter, I admit that it is slow, but because I am running levers all day, and sitting on my fanny and not lifting a single stick of wood, I am just as fast at 8 AM as I am at 4 PM, and ready to go the next day. This is what makes it productive.
Another point with equipment is, especially mini-equipment because you can get them into so many tight spaces; you tend to use them for a ton of applications that you never thought of. Here is a case in point, I bought my log trailer for...yes...getting out wood, but I live in a 2 story house, so I have also used it for a manlift when doing some trim on my eves. Mini-excavator, mini-bulldozer, a person will undoubtedly use it for a variety of things simply because they have it.
In terms of fuel:
My 6 HP log trailer uses about 2 gallons of gas per day.
My 25 HP diesel Kubota tractor uses about 5 gallons of diesel per day
My 23 HP gasoline sawmill uses about 3 gallons per day (but there is a lot of idle time in maneuvering logs however)
My cable skidder uses about 40 gallons per day (diesel)
My Grapple skidder uses about 70 gallons per day (diesel)
My small bulldozer (350 John Deere) uses about 10 gallons per day (diesel)
My big bulldozer (850 John Deere) uses about 100 gallons per day (diesel)
My Hitachi 34,000 pound class excavator uses about 35 gallons per day (diesel)
As a side note: I make more money logging using my Kubota Tractor then anything else. It is because I can get out 6 cord of wood per day and use 5 gallons of fuel to do it, where as my cable skidder can get out 10 cords per day, but uses 40 gallons of fuel to do it. However, my Kubota cannot pull wood up steep hills, long distances, or in mud or deep snow. I can often use my small bulldozer and make trails for my Kubota so that I can make the going easier, or work in unison however. Incidentally, the least profitable method, is using feller-buncher, grapple skidders, delimber, log loader to get out wood. While I can move 45 cords per day doing so, I burn 280 gallons of diesel per day doing so.
Fuel Consumption is everything in profitability.