I don't know about the 2012 and 2013 models, but I know that in the US, the 2014+ has 13:1 comp ration. The EU version gets 14:1, because their fuel is cleaner and more pure than the crap we run in the states.wait.. so is it 12:1 , 13:1 or 14:1? I keep seeing conflicting information on this for the 12' and 13' sky. Im not happy either way I feel pretty much lied to because the brochure I was given for skyactiv when I bought my 13' says 13:1 compression. 12:1 isnt even really considered high compression. I wish someone would do a real comparison of the 13' and 14' engines and tell us the real honest to go truth and how it was achieved. Does the 12' and 13' even have the volcano shaped pistons?