I have a VW Golf and they use a soft brass crush washer on the car I have MKIII generation.
If I replace the bolt without that washer there is ALWAYS a tiny leak....I can say that I have used washers a dozen times without a problem.
I think one of the overlooked reasons for the washer is to actually PREVENT deforming or stripping of the threads for the pan bolt. Because like many say here how often does anyone use a torque wrench for tightening a drain plug ?
If I replace the bolt without that washer there is ALWAYS a tiny leak....I can say that I have used washers a dozen times without a problem.
I think one of the overlooked reasons for the washer is to actually PREVENT deforming or stripping of the threads for the pan bolt. Because like many say here how often does anyone use a torque wrench for tightening a drain plug ?