Is there an ingredient panel listed on the bag? Honestly, I'm not so sure it truly matters what charcoal is used. You're going to let the impurities burn off anyway before bringing the grill into the vehicle, right? So, by the time the charcoals are burning red/white hot, there really shouldn't be any smoke - just (mostly) pure, copious amounts of CO being produced. If you can get them, 100% carbon is what you want. Some say lump style is best. The one thing I will say is that CO poisoning is not something you want to be skimpy with. By that I mean make sure you use enough charcoal to get the CO level up as high as you can. You're going to have some leakage in a vehicle no matter how well you seal it up. If you can get the level up around the 10000 PPM concentration, or more, within a few breaths you should go unconscious, which should make the death experience that follows very peaceful. The flip-side is that if you don't get the level of CO high at all, meaning quite low, you could potentially only poison yourself, resulting in serious bodily harm to yourself that you survive. If that happens, you will have to deal with the aftermath affects from the poisoning. You could end up a "vegetable", or be left with other serious neurological impairment. You could end up so bad if things don't go well that you might not be able to remove yourself from this "new" hell you find yourself in. Not trying to scare you. Just trying to impart on you how important it is to get CO right. Although one grill might be enough, I wouldn't hesitate for a second to use two, even three. Going back to that "magic" number of 10000 PPM or more - the higher the CO level, the quicker you go unconscious = the less suffering you will have to (consciously) endure waiting to go unconscious. Good luck. Hope you find the peace you seek.
Disclosure: CO is my method too. I'll be using a tent, though. And I have a meter capable of measuring CO levels up to 10000 PPM.
