Because you are assuming that you are getting 3.8 quarts out and leaving nothing in there every time you do it, or that your bike is burning on the average the same amount of oil between oil changes. The day that you can only get 3.7 quarts out and you put in 3.8 is the day that you can possibly overfill it. Anyhow, if it works for you, that is all that matters. For me, I rather add in increments and go by the reading on the dipstick once I have used my three (3) quarts.
So if you don't measure what comes out, how can you tell that you are getting 3.8 quarts out or that your bike uses no oil between changes. I don't know but from where I am from and regardless of what you claim that fits the definition of assuming or to take something as a fact when there is no actual proof or evidence
. However, as I stated, if it works for you, that is all that matters
.
Last edited by Duende01; 08-06-2012 at 12:54 PM.