I had a Fumoto F106N valve on my 2011 Kia Optima since the first oil change. I will be trading in the Optima some time this year and wanted to make sure I remembered to take the drain valve off. I let the oil drain for about 45 minutes until the dripping had almost stopped. I then removed the valve and caught the remaining oil. I let it drain for 30 minutes this time. I measured 4 1/2 tablespoons of oil remaining after I removed the valve. I know that folks always had an issue with these valves because they were afraid that too much oil was left undrained. I think that is next to nothing as most lube shops would leave much more in as they put the plug back in too soon. Other vehicles may have more or less oil left in the pan depending on the pan angles and configuration.