Yeah like C.H. said, it's not just plug and play with most engines. Some engines will require shimming at the head, a slight retune, and possibly a different glow plug depending on what you are using now. Might have to go to a med-cold or cold plug. Depending on what you are running in it now, you might not even notice a change in performance vs ?? to 30%. I've run 25% in mine with great success in the past and moved to 30% expecting more but in fact I noticed nothing and one engine no matter what I did I couldn't get anything, it actually suffered on the top end. Let us know what you get if you decide to jump up.