Still impossible to make that claim
I can build you an engine that runs cool and fine with 14:1 compression on pump gas. And I have. And I can build you another that will detonate and die quickly with just 10:1.
Without the rest of the engine specs, those numbers mean nothing, and are not an indication of how high octane fuel you need etc... it's just incomplete data.
I have held in my hand cams that require 20:1 to 24:1 compression ratio for the engine to run right. That's gasoline not diesel in case you were wondering
