All vehicles produce this. On engines with direct injection, it may coat the intakes valves. Turbo vehicles produce more blow by, because of forced induction. There is no safe way to clean intake valves, without potential turbo damage. They must be cleaned, by removing the head. Ford claims a second set of port injectors, solved the problem. They could of added a catch can instead(If it worked). It would been much cheaper than retooling the engines and adding more fuel injectors. The older, direct injection only, models should definitely have one. Ford did not want the negative impact, of new owners dumping out an oily mess, on a regular basis. They know people spending $70K, would not be happy about such a task. I doubt the EPA, would approve it.