In town gas mileage has been consistent at 30 - to - 31 miles per gallon and on a trip Texas - to California, cruising 65 MPH from 39 - to - 41 MPG. (edmunds.com)
Lighter components, including hydrogen and carbon monoxide in a mixture similar to Britain's old town gas, rise to the top of the chamber, from where they can be vented for use as fuel. (newscientist.com)