the way I thought it was measured was if you take the cylinder and take it to BDC (bottom dead center) and fill it up with liquid then you would get say, 2.5 liters of fluid into one cylinder. Maybe I'm wrong though, it wouldn't be the first time. I have a manual at home that has just about everything there is to know about the basics of every frickin engine in the world. So let me look at that when I get off work which will be.... 9-10 o'clock tomorrow morning.