Good news big John!..... I found a way for white smoke to actually be appropriate and make sense!
All ya need is snow!
I just watched this video and I thought..... That's it! Drive your rigs in the cold because that's when the exhaust is white!...lol.
All ya gotta do is move to Canada, where winter is 8 months long and your RC with white smoke will fit right in!
http://youtu.be/1VZvYjVFzkA
Mario