I am in the limousine business and operate several Ecoboost SUVs like the Navigator. These vehicles are constantly starting and stopping several times a day and their average speed is about 25 mph with all the traffic. Ford has 3 service levels which are Normal, Severe and Extreme and so I go by Fords strictest service level "Extreme". I change oil at 3000 miles.
In terms of the Ecoboost engine Ford has gotten it to the point of being fairly reliable unlike the earlier days of faulty cam phasers and such.
You can use any API SP/Dexos1Gen3/Ford rated oil on the Walmart shelf and have confidence it will work. Nearly all the oils at Walmart have all the various ratings.
The only 2 concerns when it comes to Ecoboost and oil are:
#1. Viscosity drop...the turbo engine seems to thin out nearly all 5W30s to 5W20s levels. Labs like Blackstone and vehicle makers like Ford state this is not a.concern but vehicle owners like myself dont believe them. How thin can this oil get without it being a concern?
#2. Mesh oil filtering screens inside the engine and deposits...The longer an oil stays inside the Ecoboost engine the more likely deposits will form. The most concern in regards to deposits are on these mesh filtering screens designed to block larger objects. The one of most concern is on the oil line to the turbos. If that line gets clogged it will destroy the turbo. The clogging of the screens will take some time with "Normal" oil change intervals. At over 80000 miles is where the.concern starts.
The oil I use is the cheapest I can find with the API SP, Dexos1Gen3 and Ford ratings. Lately its been Valvoline Advanced bought in bulk from the Valvoline Global Store online using 30% discount and Kirkland oil when its on sale. I change them all at 3000 miles and use a Wix XP oil filter. Wix/Purolator makes the Motorcraft filter and the main difference is the media is superior in the XP version.
The Warren oils like Kirkland and Supertech are the thickest on the Walmart shelf and do not fall out of viscosity with my 3000 mile interval.
I am guessing that more expensive oils like Mobil 1 EP or PUP might have better ability to stop deposits, but I have confidence my short 3000 mile oil drain will keep it clean inside.
I also do engine flushes at 50000 miles with the LiquiMoly engine flush and use J&L catch cans.