Same with me. Mine pulled out the 8.5 quarts. I added a full 8.5 back in and low and behold, the dash board indicator game the thumbs up "OK" and the dip stick registered same level as what I checked before I used the extractor. Given that, I think I'll just use the extractor. When you finish your experiment, let us know your findings. Just make sure you baseline everything before you run your test otherwise your results may be skewed..............