I guess so, doesn’t seem right though. Although I expect engines using semi synthetic have lasted many miles and many years. Right or wrong I have oil changes done at the dealer using what Ford recommends (semi synthetic) every 5000 miles. For a few $ more should I ask for full synthetic? Is it just better protection and peace of mind? Can’t imagine it would void my warranty? The two oil changes I had done, the maintenance minder was still over 50%. Also, I have the extended warranty of 8yrs and 125,000 miles and plan to keep the truck at least that long. I appreciate any insight and advice.
Since this thread started with a gen3 owner asking, I'm using the gen3 manual contents for 2021 as an example. While gen2 and gen3 have the same requirements (IIRC), Ford made manuals available online- which is why I'm sticking to that to illustrate my opinion.
The manual states if using 5w-30 to use oil that meets the WSS-M2C961-A1 spec, and WSS-M2C963-A1 for 0w-30.This means when looking for oil, you need to make sure the oil meets that spec. An example of this is Mobil1 5w-30, and
this pdf shows the requirement is met for a couple of different types of Mobil1 5w-30. I'm not saying Mobil1 is the best, and I'm also not going to attempt to dig into a bunch of different brands- I feel that can be left to whoever's interested in a particular brand of oil. What this means is that as long as you meet spec and can prove it through lab testing (like Blackstone labs), you're in compliance for warranty purposes. The reason I mention lab testing is that every reputable oil manufacturer will tell you the same thing. Ford has removed from the manual the line mentioning that you can substitute an API SP oil for the Ford spec oil, but it's still there for the oil filter as seen in one of my screenshots.
The Act behind any oil that meets spec being covered under warranty is the
Magnusson-Moss Act (this is a link to the final review). It's pretty long and has had a lot of rulings based on the Act. There are a couple of documents of note, however. This
review of the Act shows in plain speech that aftermarket oil does not constitute a warranty being void (in the doc, search with CNTRL+F and the term 'maintenance'). Additionally,
16 CFR 700.10 states the same and talks about warranties in more detail.
All that being said, it is solely up to you how you what oil you want to use. Keep in mind that if you do your own oil changes and use Motorcraft oil, the burden will still be on you to prove you used the proper oil and filter and followed proper intervals if something goes to mediation/arbitration/court. If you don't want to deal with any of that, keep having a dealer or independent shop change the oil and keep your receipts.