Just curious. Can anyone explain to me how a CNG/Diesel engine works. Since there is no spark plug, I am assuming it uses both fuels at the same time????? If so, what is the ratio? I am thinking about putting a proposal together for the pencil pushers at my job since we use hundreds of gallons of diesel fuel daily and was wanting to figure how much money could be saved. I assume this is possible, since my city has a new garbage truck coming that runs on cng and have seen other vehicles that are Diesel engines running on CNG.