The autoblogosphere is abuzz with the topic of “rolling coal“, apparently the practice of some diesel pickup truck enthusiasts who fiddle with their fuel systems so as to produce voluminous clouds of dense black, sooty exhaust smoke. I have to admit that when I first saw the phrase “rolling coal” in a headline at Jalopnik I thought it had something to do coal gasification and running cars on wood gas or syngas. After finding out that rolling coal wasn’t what I thought it was, I did look into the history of powering motor vehicles on wood gas and ended up finding out about these rather odd looking cars and trucks known as gas bag vehicles. Frankly they’re more interesting to me than whether or not pickup truck driving bros are blowing smoke in the faces of Prius drivers. I believe that you’ll find these vehicles interesting as well. (Read More…)