On my bigger E34 525i, I can pull an average of 10 to 15 L per 100km. But I guess slipping around in the snow, and maxxing out the heater doesn't help either.
There are a few things wrong with the layout in my opinion.
It does not allow a variety of lines to be performed. It only narrows it down to you the one designated by the barriers. Wouldn't it be boring to see everyone follow the same line?
My other concern are the clipping points. Euh. What clipping points? Instead of barriers, maybe a simple post and a few bale stacks will determine the clipping points as well as to offer a much more entertaining competition.