I recently purchased a 2008 Ford Supercrew with a 5.4l engine. Of course the manual and the dealer recommend Motorcraft oil and filters which you would expect. I have only 6000 miles on the truck and have changed it twice with MC oil and filter. I have read on BITOG that MC syn blend is a good oil, but am concerned that it is so much cheaper at Wal-mart than many others. I have always used dino oil (GTX) on 3k intervals with my engines lasting 200k and beyond. This is the first Ford that I have had since a 1978 f-150 that I had in high school, and have absolutely no experience with MC oil. So much is made on these forums about synthetic oil but I have never used and have put a lot of miles on my vehicles. I now have a company vehicle and only drive the new one on the weekend so it will probably only see maybe 12k per year. I like to change my own oil and had planned to use the MC syn blend 5w-20 to eliminate any concerns that could arise with the warranty. How well will this oil perform if I keep this truck for 10 years? Is it inexpensive because of lower quality or some other reason? Would a full syn in this thinner oil be a better choice for long term wear or does it matter??????