When Richard started using biodiesel in his car in place of gasoline he was bit worried as he said that Biodiesel Mileage was little less than the gasoline mileage. I explained to him the fuel economy which he was achieving by using bio diesel as he was using a fuel which was much less priced than the gasoline and even if he gets a little less mileage the net cost effectiveness will result in saving money for him. Not only was this he also doing bliss to the society by using a non pollutant form of fuel which was made from renewable sources.