The 5.4L Ford recommends 5w20. I've always wondered if they did this for mileage reasons or is 5w30 is really too thick for it? I know modern engines have tighter tolerances but 20 weight seems awfully thin to someone uneducated about oils like me. Will I get longer engine life from 5w30?

 

They aren't going to recommend an oil that will increase warranty claims so why not stick with that?

 

I have been running 5w30 in my 5.4 as I have 139k on my rig. Maybe I would get a bit better fuel mileage if I went to 5w20?

 

I made a post earlier regarding valve train noise on my 4.6. I never did open it up. My mechanic changed the brand of oil without my knowledge. I had consistently ran Mobile 1 5w20 as Ford stated. My mech changed it to a high mileage, high detergent Castrol 5w30 synthetic with a 1/2 quart of a product I had never heard of called striction. He also told me that he wanted the car back in the shop in a 1,000 miles.

Within 500 miles, the valve noise on startup was gone and as it approached 1,000 miles, all of the valve train noise along with a few other running noises were gone. When he changed the oil at 1,000 miles, you would not believe the gunky shetty looking oil that came out. There was no solids, but the oil looked like it had not been changed in a long time. It also had a funky burned smell to it. He told me not to worry, that was what he expected.

As he put the fresh oil in, he just smiled and said, see you in 3,000 and then we will put it back on 5,000. At the 3,000 change, the oil looked a lot better, still dark, but clear and no smell. I am now on the 5,000 cycle again, no noise at all. I do not know if it was the oil, the striction, a combination of both or if he just waved a magic wand, but what he did saved me about $1,200 in repair cost. It just rolled over 200,000 miles and is running strong. I may just make that 400,000 with it.

So really, I do not know what caused the chain noise to leave, the weight change, the addition of the striction which is supposed to clean up the oil system by removing the gunk in narrow passages or just luck. I do not think any damage was done because if there had been, I would hear it, see it or smell it by now. One other thing I noticed is that the front crank seal has stopped leaking. But hell, if a Ford did not leak, it is not running. I have never had one yet that did not leak somewhere. LOL

 

I see no problem running 5w-30 in the summertime, in a 5W-20 engine.

 

Well I guess I will continue running 5w30 in my rig

 

I looked in my owner guide, Ford calls for 5w30 for my rig

 

They can be behind the curve . I started using synthetic before FORD recommended it. My choice was based on info I got from serious tests by engine designers etc. All the oil companies have synthetic at this point --it works !!

 

Was the additive called Hot Shot Stiction ?

 

That is what he used. It surprised the hell out of me.

 

I tried 5w30 for once cycle, phaser noise went away briefly, then came back about a quarter way through the cycle. I did notice my truck needed a bit more throttle input to accelerate like I normally would though, so I went back to the 5w20.