You made two statements:

> Seems a bit odd to tax the same oil twice.

I'm not sure what this is in response to, however there are many, many situations where various government entities will tax something as many times as it can. I am only responding to this comment as this is something that I find particularly reprehensible given my libertarian bent.

> I don't see anything abut driving on another fuel that should exempt one from paying for road maintainence.

This is a well-made point. I get the impression that many people choose to make and run bio-diesel in an effort to avoid paying taxes on fuel which contributes significantly to the cost of fuel. In California, we are presently paying $.60 per gallon in state and federal taxes. I'll applaud someone if they want to stick it to the man and not pay taxes, but they certainly aren't helping the rest of us that do pay taxes. That all having been said, I'd rather that more people were up in arms over egregious taxation... again with the libertarian bent.