I went to the store to pick up amsoil 5-20 (yep switching Now) and the store guy says with 60000 miles on it you should be using 5-30 he continues to say as the engine gets up in mileage then up the thickness, I have heard this from time to time but I don't recall reading it here.
So is there any truth to it or should we just stick with what the cap says ?
I went with 5-20.

Also I'm sending Blackstone an Oil sample now and one at the next oil change just to see if there will be any positive changes.

And by the way the 5.4L is running better and smoother the last 500 miles than it ever has, I like it more and more every day.

P

 

5W20...60,000 is not "a lot" of miles on that motor.

 

IF the Ford Engineers wanted you to run 5-30 they would have put in on the cap! Stick with the 5W-20 ALWAYS.

 

I don't have a 5.4, I've got a 4.2 that's pushing 190,000 and I still use 5w20. It leaks about 1 qt between changes at 3000 mi due to a rear main. Still doesn't burn any. I'd stick with the 5w20.

The idea of using thicker oil is old school and does not apply to todays motors.

 

I have the 5.4 with 135,000 n it. All it has ever seen is Motorcraft 5-20 and it barely moves on the stick between changes at 4,000 miles.

 

Listen to the guys that engineered you're engine, not the guy selling you the oil.

 

I ruptured 2 discs in my back so I can't change my own oil for a while. I bought 3 oil changes at a local tire store on Groupon.

The 20 something oil changer/cash register clerk added 10W30 to my car. The owners manual states 5W20. I asked why and he condescendingly said 'Well sir this is Az and you really need the heavier weight oil". I told him that may have been true in 1975. He did offer to drain it but I am not one to waste oil. I figured damage would be minimal in 3000 miles.

The entire store is run by a bunch of 20-30 somethings, wearing sunglasses inside and with a know it all attitude.

I am always amazed that they actually believe they know more than automotive and lubrication engineers. I think the proper term for these types is jackass!

 

Tell the KIA that he can put molasses in his car if he wants to but as long as he's working on yours he'd better put in what YOU want.

 

While I agree the 5W20 is "THE" oil for these engines, I am running a test that so far indicates no harm will come to them using a heavier oil. There are no benefits to running a heavier oil, but no immediate harm comes from it.

Background: I have a small "fleet" of trucks, cars farm equipment and small engines, diesel and gas. Having four or five grades and brands of oil has been a pain so I wondered if I could consolidate with a "fleet service" oil suitable for gas and diesel engines. In researching what's available at a reasonable price, and the viscosity requirements from the OEM of the various engines I have, it looks like a 10W30 HDEO would work in everything and fit within the all recommendations but one... my '05 F150.

Seeing that some people run a heavier oil (by accident or due to some delusional idea it's "better" in some way) without the engines grenading, and 30 grade is recommended in placse like the Middle East and Australia, plus noting that TSB where 10W40 is spec'ed as a band-aid dealer fix for engines with noisy phasers, I felt satisfied I could experiment a little without too much worry beyond wasting a little oil.

I can datalog many fuel injection parameters, plus oil temps, and I have a "real" externally mounted oil pressure gauge. VCT was my first concern, so I datalogged the VCT in various situations with 5W20, then installed a crankcase of Motorcraft 10W30 Super Duty diesel oil (a dual SM/CJ-4 oil) and datalogged again in similar driving situations. I couldn't see a difference in the data... but that was during the summer and fall. Winter will be the big test due to the 10W30 not having anywhere near as good a cold flow characteristics as the 5W20. Tests are ongoing....

I do note the oil pressure is higher (33 vs 27 at hot idle, 66 vs 60 hot @ 2000 rpm... "hot" being 190-195F) but that was expected.

So, everyone who says 5W20 is best for the Modular is right (with a few specific exceptions for some driving situations) and optimal for 99.5% of all F150s. All I'm saying here is that your engine won't immediately grenade, run differently or be harmed by some dwebe putting in 10W30.

BTW, I have been running accurate MPG tests as well (before and after) and I can't see any differences showing up. Been testing the heavier oil since April 2011 and I really don't note my average going down. I think it might if I was a short hopper, where the oil never got warmed up, but when I start the truck, I almost never drive less than 20 miles at a stretch so the oil always gets warmed up.

 

In the standard 2 valve conf. I understood the modular oil was 5/30 before politics came to play on new fuel economy "standards." In other words same motor just different standards, nothing connected to "engineering," per say.

I found an interesting anecdote of a guy trying different oils for 4.6, and he noticed a 1 mpg drop in economy on using 5w30 full synthetic vs. the 20 half-dino oil. (I believe this was posted on that message board: Bob the oil Guy, sorry no link.) Interesting

I've experimented with Amsoil: 0-30, 5-30, 5-20.

The 20 weight will leak a bit at valve guides ( hopefully seals) as there is some usage between changes. There is that traditional hallmarked blue puff on start up, from sitting overnight.

30 nothing.

 

 

Yeah.....the computer must have told him that because many of these "certified parts experts" can't think for themselves.....no way, not even close!

 

ive always put heavyer oil in my 4.6L because my 1994 4.6L merc grand marquis took 10W40 so yeah. plus 160,000 miles

 

Thanks for all the answers I did put in 5W20 just full synthetic Amsoil rather than the Motorcraft, I guess I will see if it worth it or not but I do believe it runs a bit more quiet, I can hear the injectors more clear I guess would mean less other noise.

To MLD my engine has been using oil from day one anywhere from 1- 1 1/2 quart between oilchanges at 5000. I told the dealer but he said its kind of normal some will use and some not as long as it doesn't get any worse which is has not, it will however be interesting to see it the Amsoil will be the same.
And if the mileage will increase I doubt that though,

Thanks