I had my ST3 for 3 and a bit years, up until it hit 60k it didnt use a drop, then the usage went up to about 0.5l to 1l between services, which was 6ish months for me,it also felt a little quicker when it used more oil, so maybe it had loosened up.
yeah its just hit about 20k so is run in now lol, as i said the guy at ford today said that it was normal, no visible leaks or anything and its being serviced on the 3rd so will get fresh oil and I will check it more regularly