The bit I was referring to is, "B30 is 30% mineral Diesel, 70% Biodiesel", which I think is the wrong way around.
On Wikipedia, there's usually a group of people who oversee a collection of pages on a particular topic and monitor any changes that are made by other contributors. They will discuss anything that they're not sure about in the page discussion and come to a consensus. Incorrect or out-of-keeping edits can always be reversed and a reason posted in the page discussion.
I quite understand about not wanting people to mess about with your hard work, which is why I wanted to check before leaping in. On the other hand, the great strength of something like this is that, with many more people involved, the final result should be better and more comprehensive than any one individual could produce. The flipside is that an author has to be prepared to "let go" of their work and accept that others might think that they can improve upon it.