Originally Posted By: oil_film_movies
That engine, with turbo, is actually breaking apart some of the chemicals that hold the viscosity (thickness) high when hot, known as VII (viscosity index improver) chemicals, resulting in low hot viscosity here. I think that is why Ford specifies the use of 5w30 instead of 5w20 in this particular engine, because they expect this to happen and the engine has plenty of ability to cope well with lower viscosity when it happens.
Iron comes from so many steel parts inside your engine. Its friggin' everywhere. I replaced my normal drain plug with a strong magnetic drain plug for the purposes of grabbing any iron (Fe) particles floating by in the night.... Brands 'Dimple' or 'GoldPlug', google that to buy online, are the best.
While some shearing may have occurred, the majority of the reduced viscosity is likely caused by fuel dilution that is common in TGDI engines. Keep in mind that, because of its methodology, Blackstone is essentially useless when it comes to quantifying fuel dilution.