It's the same stuff. I'm not sure how much of it leaks, but you have to either flare it or use it for something or it leaks anyway. Using it for cars and trucks

It's the same stuff. I'm not sure how much of it leaks, but you have to either flare it or use it for something or it leaks anyway. Using it for cars and trucks is basically flaring it but using that energy for propulsion. The taxes are not based on that, though. They're strictly interested in tailpipe emissions (not even lifecycle emissions), and don't recognise biogas at all. I'm planning on switching to a BEV eventually, but right now it's not financially possible. Most of the time I commute on my bicycle anyway.