Does anyone know more about the source of the antifreeze corrosion rates given in the FAQ? I've tried e-mailing the reference, but the msg. doesn't go thru. Are these cast iron or aluminum corrosion rates? How does the BMW 'holy water' compare? Bottom line question, do I buy BMW sauce or save money and buy Zerex? Thanks in advance, Barry Ritchey '90 325iX '95 203cm Tua Montets '94 AHD 9'-2" '85 Levi 501s '57 Birthmark