"Never change a crush washer" on the oil drain plug.... eventually, the crush washer and drain plug become one. I have seen that happen and I had to replace the drain bolt just to use a new crush washer. I have also ended up missing putting the washer on the drain plug. Do it just right and quickly, you will not even lose an ounce of oil. Feel where the last of the threads are while holding the bolt straight in, turn a little more to drop past the thread lip and now you are ready to switch the bolt with your finger. Slip on the washer and go for another switch, but be prepared to give the bolt a little bit of a turn to help line up the threads and close off the flow. I lost so little, I did not even bother putting it back in. That was the 0.1 quart out of the 4 that does not need to be there.