Hello, the compression of a cylinder depends 1º on the tanks of the rings with the cylinder and 2nd the closure of the valves, in the first case there is consumption of "oil", consumption of gasoline little power and failures in the cold start mainly, in the second case low compression giving little difficult potness to start and excessive consumption of gasoline Excessive consumption of gasoline, conclusion: no engine can perform perfect combustion with low compression, performance is "bad" we talk about good performance when an engine consumes proportionally to the potion it gives us.
greetings.