My response was to visionguru and testing. We already have the testing done for us was my point. It is a user decision, and one user decision is not more right than the other. I personally have used only 93 in my 18 accord since I bought it last month.@tisuanhoc87 asked about fuel as it relates to high elevation. Regular fuel is 85-octane up there. 87-octane is mid-grade fuel up there, like 89-octane is mid-grade at lower elevation. Knowing that he can safely run "regular" 85-octane in his NA Civic, he wanted to confirm that he still needed 87-octane in the new Accord due to the turbo, even though it is considered mid-grade octane at high elevation. I think his question was more about avoiding potential engine damage than using higher octane to boost power.