I was talking to a neighbor at my marina yesterday about fuel additives. He's got a go fast Skipjack that he uses for diving and fishing. He was saying how much 85 Plus diesel fuel additive improves the performance of his engines - reduces smoke and improves mileage. I was not familiar with the product. I use an additive to deal with the organics in my tanks but not a performance enhancer. Is a performance enhancer necessary for my low consumption Lehman 120?