AFAIK RMV Germany started with the Blast series as a way to use up old stock. Then I think Answer RC got in on it, then RB USA... The current one is the V14, and on paper anyway looks like the V12.. Not sure about a V13.. I'm still trying to sell my V9, and when I do I'd probably get the V12 or V14, as I'd expect them to have more power.. (The V9 is meant to be a smoother buggy engine I think..)