Long ago, I had bought a brand new Ford explorer. During the first 1000 miles (mostly highway driving) I checked the mileage. I was doing a cross-country trip. I pulled into an oil change place and had them put in a synthetic oil and slick 50. Over the next couple of tanks, I gauged the mileage. It had bumped up by between 2 and 2 1/2 miles per gallon. For the explorer, this was about a 10% boost in gas mileage. I am curious if EM was going to start them out with a treatment like this as a factor to get them to 84 MPG. If not, is there any reason to NOT do it to an Elio once it gets off the production line?