So here is a comparison that I’m sure nobody has done yet. My car is a 2011, bought brand new in March 2011. Build date is December 2010. This is my 5th Mustang, all manual cars. This car is not my daily driver and as of this post, I have 2000 miles on her. With all of the 11’s and some of the 12, we started out with Ford Motorcraft QS fluid. In cold weather I would experience the 1-2 lockout or nibble. I also had the gears grind on me twice. Once it warmed up, it was ok, but still notchy. June 2011, I had 900 miles on the car and switched to Red Line MTL. I immediately noticed a change in every gear. Since it was already summer, I could start out with a bone cold car and shift with one finger. The ease and smoothness with the MTL was awesome. However, it is a lighter oil than the factory fill. This concerned me because summers here are in excess of 100+ everyday. I ran the car throughout the summer and all of fall with no problems. I never experienced any gear whine, lockouts, or notchy shifting. Since it has been getting colder than crap here, I have been experiencing the 1-2 nibble. I would have to shift from 1-3 until the MTL warmed up. The past month or so, the new rave is Amsoil MTG. I bought some and switched it out this morning. MTG is the same oil weight as the stock QS fluid. Unlike the stock fluid, MTG is a FULL synthetic oil. I drained the MTL to save just in case I do not like the MTG. Once I drained the MTL, I noticed something I did not like. Metallic coloring/sparkles….. Nothing large, but there was enough in the MTL where I could see the majority of the oil was completely saturated in this microscopic metallic soup. Could this have been from running a thinner oil most of the year? Filled the car with Amsoil MTG this morning and immediately noticed that it was nowhere as smooth as the MTL. Outside temp was 50 degrees. There was a more pronounced 1-2 nibble and every gear did not feel as smooth. Once I drove it enough to warm the MTG up, everything smoothed out, except for a slight 1-2 nibble. Down shifting is silky smooth except when coming to a stop and slipping into 1st. It takes a little more effort to slip into first before you come to a stop. One thing I do like, is the MTG is the same specs as the factory fill and far exceeds all the factory specs. Summer time will be the test for me. I’m sure once it gets back to 100+ during summer, the MTG will exceed the Red Line MTL in protection. So my take on all of this is getting the factory crap out of your car ASAP. If you live in cooler states, I would recommend Red Line MTL. If you live in HOT climates during the summer, get Amsoil MTG. I think MTL may be a tad too thin in hot climates. If you use MTG, then you will not have as smooth of shifting as opposed to using MTL in the winter. I’m sure MTG will be very smooth when it starts warming up again. As far as the TSB that Ford put out for the QDC fluid, well, that stuff is thinner than most automatic transmission fluids; so run that stuff at your own risk. I’m still concerned with metallic stuff in my MTL oil when I drained it. I still have no whine or grinding.