When I was a child my dad was talking about the water for fuel cars. This was in the 70's. In the 90's my cousin and I did the water+gas car. It increased his mileage by 25% right from the start. I know that,with some work we could have done a lot better.  My cousin also had a diesel truck that he rigged to burn oil. He ran the diesel for 5 minutes giving the oil time to heat up, then switch over to oil. About 5 minutes before before reaching his destination he would switch back to diesel to clear the lines of the oil. He got 1500 miles to one tank of diesel!  Yes, there are drawbacks to it. He gathered used oil from restaurants. They would gladly give it to him! He then had to store it. He had to filter the oil before using it. It had to be free from food particles. Pieces of chicken nuggets will plug up the works! There was a little work involved, but it saved a ton of money! Also, your exhaust would smell like whatever was cooked in the oil! There has been great ideas and inventions that would be very good for the people! Good for the people is not what the wealthy want. They shut you down, before quick, if you come up with something that they don't profit from!