in 2012 mazda released their SKYACTIV engine that runs 13:1 on 87 octane. So i agree with funwithfuel, there are more parameters that have to be considered.
With statements like this, you prove yourself more and more ignorant about automobile engines. Not trying to insult you, we're all ignorant about things. But you refuse to listen to experienced people after you've asked for help and then you try to wrap an old style engine with new computerized engine rules.
So, once more. And I don't give a rat's *** what the previous owner said. There's no way in hell to run 13:1 compression on 87 octane in a carbureted naturally aspirated engine like you have. IF the previous owner really did it, then your engine does not have 13:1 compression. It's really that simple.
People are coming off as harsh because here we are almost 3 pages deep and you're still being bullheaded while people who've been there and done that for thirty and more years are giving you correct answers. You are simply looking for the answer you want to hear, that a 13:1 engine will run on pump gas and it will not.
No one is intentionally trying to be insulting. Everyone in the thread so far is really trying to help. You need to start listening, instead of arguing. Then you might get something accomplished.
