Oil Leak
You could just pop the bolt and quickly insert the washer and bolt back in, but it'll get messy and you'll still have to top the oil off. Cheaper than dumping out all of the oil though. I'd try fookoo's suggestion first thought since it was their mistake.
I have never seen a washer on the oil pan since the first day i have it!!
Thank you in advance.
When the Goodyear folks changed the oil, what kind of oil filter did they use? paper media type or fleece material filter?
If you are convinced that they indeed used the 0W-40 oil when they changed the oil and it's relatively new and clean looking, then no problem in reusing that oil.



