This VP leaded fuel will be the first choice for those who are not restricted by fuel regulations as it offers the largest "bang for the buck" of any performance part that can be purchased. VP U4.4 will provide a large horsepower gain across a very wide range of applications. It has been designed to be used in stock or modified 2-stroke and 4-stroke applications. It is common to find that jetting changes may need to be applied (ie. +2 main or pilot jets).