It's an impossibility, but let's imagine for a moment that I could add a few drops of dish detergent to water (work with me here ;-)) and put it in my car's tank and it would work. Could they charge me for doing that? That's kind of a kooky example- but I wanted to go to the extreme right away. Surely they can't imprison you for that or even claim to be able to.
What these people have done is come up with an alternative fuel. It's as if the gov't is saying you must use diesel or petrol in your cars. What if I invent a motor that runs on air? They can't tax the air. What if I invent a fuel injection system that gives me 300 miles to the liter. That would be evading the tax as well if I installed that injection system on my car.
Ach, it's useless to complain. I suppose when I get sick of paying the high prices of petrol here, I'll move somewhere else.