Yes. They're suposed to be replaced everytime the drain plug is removed. They "crush" when installed so are essentially one time use only.I was at the dealer getting some warranty work done today and I picked up a few oil filters for my 6i with 2.0 spin on conversion. The parts guy gave me a crush washer to go along with each filter and said they usually change those with it. I've never noticed a crush washer before - is this for the Mazda 3's drain plug?