I go through a fair amount of diesel fuel, but it's mostly short trips. The commute with my 1985 300D is about 15 minutes, so it's barely getting warm by the time I get to the office. My farm tractors also do mostly short jobs, with the occasional long job. My diesel lawn mower, on the other hand, does relatively long jobs and then sits idle for several days to a week. I'm thinking that the WVO thing isn't going to work well under those circumstances. It seems like it would work better if you are getting the motor good and hot on a consistent basis. Do any of you WVO proponents see it different?