Repair/VIDEO/Vehicle: Wood Gas?

Just hen you think ther are no more free ways to get energy, up pops another. All you got to do is look to see what North American Energy producers dont want you to see....You tube. Wood Gas? Never heard of it? Me either but hers a video of it being pumped into propane tanks as an alternative fuel source. And here in a truck And here in 1941 gas powered truck. Amazing that people have known about this along time but yet, something renewable is not used again. Hummmmm