[CloudsInMyCoffe]

OP - I asked myself the same question and started searching the Internet. I have been using the Motorcraft Synthetic Blend with a Motorcraft Filter. My reasoning, misguided as it might be, below:

From what I can find out the Mustang was shipped with Motorcraft 5W-20 Synthetic Blend. It has the xxx% Oil Life indicator, which I wanted to use. In order for this to work they would have had to pick an oil for the constant in the algorithm to calculate the percentage. It would stand to reason that they used what was shipped in the car.

I drive around 2500 miles a month so the oil is changed every 8 to 10 weeks. Considering the change frequency Full Synthetic seemed a waste. Admittedly I have not let the % get lower than 30% -- I still have that "every 3000 miles" oil change mentality, but am putting forth an effort to change.

In addition to that I read "good things" (vague, I know) about the Motorcraft Synthetic Blend on Bob Is The Oil Guy.

Everything you ever wanted to know about motor oil and more:

Bob Is The Oil Guy
- Bob is the Oil Guy



From the 2013 V6 Manual

Oil:
•Motorcraft SAE 5W-20
Premium Synthetic Blend
Motor Oil (US)
•Motorcraft SAE 5W-20
Full Synthetic Motor Oil
(US)
•Motorcraft SAE 5W-20
Super Premium Motor Oil
(Canada)
•Motorcraft SAE 5W-20
Synthetic Motor Oil
(Canada)

Filter:
Motorcraft FL-500-S

 

[CloudsInMyCoffe]

For $25.00 you can get your oil analyzed at Blackstone: http://www.blackstone-labs.com/ -- I have not done it yet but I'm sure curiosity will get the better of me at some point.