Only 10% of the oil gets filtered? How does it manage to do that? Is there a separate reservoir for that 10%?
If there are 4 quarts in the crankcase and one in the filter, 20% of the oil is in the filter at any one time.
If you are looking for an excuse to run without a filter you need a different one than "a Chevy 235 filter only filters about 10% of the oil".
