David, nice to see you rationalising it all. However, I have been using it since I made the first post in this thread (@60ml per 38 litres) and have noticed a marked increase in power at the low end and a noticeable improvement in diesel consumption. This is with both bio and dino fuel. I think the power improvement means I use less throttle to get where I want to when taking off, thus leading to the improvement in fuel usage. Whatever, it is working for me and I'll keep using it. Now, I wish I could stop breaking CV joints in the bush.