I'm making the switch to GC 0w30 from M1 10w30. I just was not getting the wear I'd like with M1. I'm going to try GC a few times to see how it does in my LS1 and 5.3 Vortec. It is thicker then M1 10w30 so it will be intresting to see what happens! I found 12qt of GC at Auto Zone. I hope I got the right Syntec. It says "Made in Germany" on the back on the bottme left side and that was the only difference on the bottle. All the bottles had a little oil resadue on them kind of like M1 bottles but when I squeezed them they were sealed up tight. My engines seem to be quiet on M1 so I wonder how they will sound on GC? I'll make the switch as soon as I hit 3,000 miles on this last M1 run. My engines burn no M1, does anyone here using GC burn it? I hope My engines willnot start to burn when I make the switch!