I used this wrench for my Passat 3BG 1.9tdi 74kW oil filter cap.
Printed the 15mm version and used a hammer to open the housing.
Print with something harder than PLA !
Your engine is hot and makes your printed part weak !
My wrench worked and if you screw one side up you can flip the wrench and use the other side !
Stress analysis shows a 200N force at the laverage.
I had to use a hammer to open my filter housing so i made this thing strong enough to get hit.