My 97 Mazda has 105k miles on the 1.5 liter engine. I have 3 bottles of Auto RX and 3 one- gallon jugs of Mobil 1 10w30. In addition, I have the old stock Mazda OEM filters with teh silicon antidrainback valve. I'm like a kid in a candy store with all this hardware and chemicals. I am at 4500 miles on my supertech full-syn 10w30 oil. Should I use AUtoRx in this oil, or should I drain it and fill it with cheap dino for the auto rx treatment(s). I plan on running two treatments of Auto Rx as per instructions on web site for automobiles with > 100k miles. What do you guys recommend I do with teh third bottle of Auto RX. The price was too good ta pass up that third bottle with their special! Guys, I am fired up and excited. I can't wait to take the engine to the redline after the Auto-RX treatments and Mobil 1 in the crankcase with teh OEM oil filters! Life does not get any better than this!