OK, with my Arx treatment rinse phase nearing its end, I had decided to use a mix of Pennzoil or Chevron 10/30 with their 15/40 oils, as my 1st "normal" oil after Arx rinse. So, calm and collected I went to the local Auto Zone here to buy Pennz.LL and just looked at the Castrol shelf out of habit...and what did I see? GC! about 20 bottles and none of the US-yellow label stuff!!! I asked the AZ guy and he said this is the oil they will be getting from now on($4.99 per qt). This is the stock no: MO 23386B784 1900 I had been searching for GC a while ago, before I knew that my car was burning/leaking oil a bit, and with Arx, I had pretty much given up on syn.oil, fearing of new leaks. I couldn't decide what to do, so I didn't buy ANYthing and came home! Back then when GC came out, I wanted to use GC, but after my oil leak(not big) with syn.Pennzoil started, I have used Arx with Chevron dino oil, and now the Arx treatment is almost over...and the oil level hasn't dropped a bit. However, I'm not happy with all the cold noises I've been getting with Chevr.supr. 10/30 at temps between 15-32F... Advice me: Last time I switched from dino to syn at 85,000 miles with NO engine cleaning; now that I've cleaned with Arx, should I be brave and make the switch to GC? will it start a leak/consumption again? or should I surpress my GC-desire and use dino Pennz 10/30 15/40 mix??? but the GC bottles looked SO inviting.. GC (and other) Gurus out there, please help me make the hardest oil-decision I ever had to make... (1997 Ford T-bird 4.6L sohc, 92k miles; as far as I know noone has used GC yet in this type of engine) Sorry for the long post; Thanks a mil in advance.