I use a cetane booster and when I change the oil I put a qt of greased lightning in it. Paid off a while back . when I was down and unable to walk or drive my wife and daughter talked me into letting them drive it around. Long and short of it is the oil plug worked loose and they ran it for over a week w/o diddly for oil in it. When I changed the oil out (madder than a wet cat) there was maybe 2 qts of sludge left in it. Changed the oil out fired it up and it ran like usual........ I attribute that to the greased lightning thats exactly what it says it will do. It's a molecular bonder of some type similar to slick 50 but this stuff actually works.