Here's the latest UOA on the Mercedes in my signature. Mobil 1 is still doing a great job. I've not been driving the car as much, and while the OLM starts telling me to change it at a year, I went 15 months.
High Ir? Ir = Iridium. I didn't know they tested for Iridium. The problem would have to be severe for a spark plug material to make its way into the oil. Iron = Fe.
Chemistry jokes aside, I don't see a problem with iron in this UOA, or any of the priors for that matter. How does a reading below universal averages qualify as high? Most people associate the words "below average" with "low," not high.
Yeah, the whole Mobil 1 high iron thing is old by now. The evidence it was based on was thin to begin with and is now obsolete in any case. The idea is just taking its time dying.