Wondered if someone could advise of sizes needed to do whole fuel system. I have read through previous posts and it seems "O" rings from MB dealerships are still rubber and not Viton. Due to a lack of workshop, ability, knowledge, and about a foot of snow on the ground its going to a local garage who said he would just order up from the MB dealer. However, it would seem from reading through posts that Viton or Nitrile are best. Hence I need to know what sizes to buy to take with the car when it goes in.