I have 2000 F150 XLT 5.4L. My owners manual calls for 5w30 oil. I have heard rumors that even though this is the case, Ford actually now recommends 5w20 for my particular engine.
I called my dealership service department today, and asked the guy. Without hesitation he said, "use 5w20". I asked him about my owners manual, and he said, "well our parts department has the list of what oils to use with what engine." So he transfers me over to the parts department, and they told me to use 5w30 since my engine is pre-2001!
Now I realize it probably won't make much difference which oil I run in my truck, but what gives? I just want to know what the current real recommendation is from Ford and which one would be the better choice, all other things equal.

 

Ford has back spec'd 5w20 for that engine. I would have no issue using 5w20.

 

Even for towing and heavy-duty operation?

 

No for that you must use a 20w50 All kidding aside the 5w20 will perform great for heavy hauling or towing. We use 5w20 in our fleet of 5.4 and 6.8 trucks which pull 10k on a daily basis most have well over 150k and up to 265k with no ill effects. The uoa's come back single digit wear so the oil is doing a great job.

 

Check out the link below. It shows which oil Ford recommends for all of their engines. Your engine calls for 5w20. So does my '97 4.6L, but I run 5w30 & 10w30 in it. I bought a boatload of Havoline synthetic & QS semi-synthetic 5w30 & 10w30 last year, before I had any clue that my engine had been back-spec'd for 5w20.

Motorcraft Oil Chart

Personally, I can't talk myself into running 5w20. My '97 4.6L engine has been on 5w30 & 10w30 for so long, I'm afraid a 20wt oil would be too thin at this point. I could very well be wrong, but I would lose sleep if the engine had 5w20 in it now.

 

That's kinda how I feel too; that 5w20 is pretty thin stuff. However, I can appreciate its advanced technology, so I'm not too worried about it. If my engine was high mileage and using a lot of oil, I would probably stick with a higher viscosity oil regardless of spec. Anyone whose orginal owners manual calls for 5w30 certainly won't do any harm by sticking with that instead of the 5w20. But thanks to everyone's input here, it sounds to me like the 5w20 is the better choice in most cases.

I was pretty certain that Ford had back spec'd a lot of pre-2001 engines for the 5w20. The real question is, if you and I are aware of this, then why the heck didn't my dealership know that??