At one time it was suggested that Mobil 1 produced higher than average iron levels in OCI's . A number of people suggested it was only temporary due to a hurricane which hit Texas disrupting the availability of additives Mobil uses in their Mobil 1 oils . Here's my view : Mobil is a giant , sophisticated, synthetic oil producer - why on earth would Mobil knowingly produce a synthetic oil that resulted in higher iron levels for their valued customers versus what is considered acceptable and at an equal level (or below) than their competitors who make synthetic oil ??