I use this methed in all my sirio engines its not for all engines but sirio i can say yes it is the only way to go but you defnatly need some exprence or need to see some one who is exprenced with it first. The key to useing this run-in safely is the engine wile at full "WOT" must be so ritch that it dose not rech much more rpms than at idle. There is a very short vid at the sirio web site under "extras" and run in for on-road it shows a kyosho evolva with a sirio 21wcr engine being run in useing this methed. i sugest you watch it many times and ask some very exprenced racers about it and watch some one who knows how to do it befor you try it. All the engines i have done this methed to have been above most in paformance and lasted a very long time and 100% run-in after only 1.5ltrs of fuel. My advice is take your time and fined all the info you can and some video's of this methed befor you try it. Regards Jeremy.