I'm running Mobil 1 10W-30 with a 3oz maintenance dose of Auto-RX in my 98 chevy truck with the 5.7L. The oil has almost 5,000 miles on it and is still a light amber color. You can easily see the dipstick through the oil. I've only had to add 24oz of oil so far which is less than I use to add. I think Auto-RX has did what it is supposed to. I'll be doing an oil analysis in about a 100 miles to see how the Mobil 1 has held up and to see if the Auto-RX has decreased wear at all.
Wayne
Wayne