Originally Posted by UrabusDenis

I think you have nothing to lose by using ARO. Although I'm pretty positive that it isn't needed after a quality fuel is used, I still use it for precaution. It's not a problem for me to pop off the air filter and pour some ARO. My engines have always looked perfectly clean inside and I didn't notice rubber damage. What you must take care of is that your ARO doesn't damage the silicone insert in the crankshaft (if you have it). Most of the RC AROs should be safe to use