So as the season nears an end in new Engladn I have started buying my fues by the quart. It could snow any day. Why have a full gallon..? I'd like to try 30% nitro in my matrix buggy. Would I need to make any changes to my engine or setup to run 30% nitro or is it just plug and play?

You will have to richen it up a bit if you are going to switch to 30 percent. Some motors you have to shim the head also.

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.