5W30 or 5W20.........

[Erich Zeppelin]

I've been using Castrol 5W30 with a Motorcraft filter, I've heard that I should be using 5W20. Can someone tell me what the factory recommends? Sometimes I have the "startup rattle" and was wondering if it was my use of the wrong weight of oil..........

 

[GAINMOB]

my 04 is 5w20...factory recommendations but its going to depend on what part of the world youre in and weather conditions...since youre in alaska...if i remember right they recommends heavier weight for colder weather...you do go below 0 for an extensive amount of time

 

[Erich Zeppelin]

Down in the lower 48 for awhile, I've lost my factory manual, but I've heard both weights were the factory recommended............

 

[GAINMOB]

where in the 48? florida you'll want w20...but you cant go back to alaska with that...actually...you'll be fine with w30 depending on how long you'll be down here...if you drove all the way down...guess you could change it out in washington if you took ferry or before you cross into canada

 

[BakerEdition]

Mine is a 2000 and I got it with 77,000 and have just now rolled 100k...I have had that start up rattle since i have had the truck...I have tried everything from synthetic to mulit-weight and have tried different 5w20 and 5w30...and that rattle is always there...factory calls for a 5w20 on this 5.4....im beginning to wonder if that rattle is not one or two of the catalytic converters....the stuff inside being loose and after it heats up it expands and goes away....

 

[toms89]

my 04 is 5w20...factory recommendations but its going to depend on what part of the world youre in and weather conditions...since youre in alaska...if i remember right they recommends heavier weight for colder weather...you do go below 0 for an extensive amount of time

5w-20 is factory recommended as said. Surprised its not on your oil fill cap.....

But it is the opposite as far as cold vs hot climates. Colder climates can go lighter weight oil and hotter climates heavier weight oil. This is because the colder the oil the higher the viscosity.

As the engine ages and tolerances open up you can try heavier weight oil to see if it helps.

Most newer vehicles are recommending lighter weight oil today to help with fuel efficiency.

 

[toms89]

I've been using Castrol 5W30 with a Motorcraft filter, I've heard that I should be using 5W20. Can someone tell me what the factory recommends? Sometimes I have the "startup rattle" and was wondering if it was my use of the wrong weight of oil..........

I would say the startup rattle has nothing to do with you running 5w30. I would say either the oil filter is letting the oil bleed out when it sits or its excessive wear on some engine components.

How many miles??
Stock motorcraft filter??

Not all oil filters are the same...some allow oil to bleed down. I stick with stock motorcraft filter myself after having issues with various other brand names.

 

[Captain Morgan]

I second both of toms89 posts.

Since I live in WA state my engine never gets hot, and is never going to get hot. I run 5-20 and unless I was using oil due to engine wear, there's no reason to use anything heavier.

That's a far cry difference from someone in Flagstaff on a hot August days sitting in bumper to bumper traffic with the A\C on. Would an engine just burn up with 5-20 in it on that day? Doubtful, but as stated the viscosity is lower and over time might contribute to increased engine wear.

Personally, on vehicles that do not consume oil or have leaks I prefer to add a bit a Marvel Mystery Oil to the crankcase too, along with some in each tank of gas. Does 1\2 cup of MMO decrease the viscosity? You would think so but this thin oil actually has a very high viscosity so it wouldn't burn, even on a hotter engine.


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[darmahsd]

One of the reasons 5W20 is called for is for better fuel mileage, which is always a major topic around here. I use Mobil 1 synthetic, but I bought a big ass Earls engine oil cooler and
will switch to the F250 14 row transmission cooler 'cause heat kills components more than viscosity numbers. Even my wife's Hyundai Elantra, with a small, high winding engine with more power per cubic inch than the 5.4 Ford, calls for 5W20. Modern materials, better rated oils and closer tolerances make the heavier viscosity oils unnecessary in modern engines. My 1981 Ducati motorcycle has a roller crankshaft with
a lower oil pressure oiling system. That is where I need to use 50 weight oil.

 

[alaskanexpy]

if i understand it correctly the 97-98s call for 5w30 and the 99-up call for 5w20.

i ran 5w20 in my 98 for about 10k miles, then i switched back to the 5w30 the truck calls for and it had a rattle at start up with the 5w20 that is now gone with the correct weight 5w30 in it.

 

[Erich Zeppelin]

Thank's guy's, I called Ford and was informed that the 1999 Expedition takes 5W30

 

[tsgrpr97]

I read that the only reason Ford switched from 30 weight to 20 was to eek by tighter cafe regs. No mechanical differences. Next oil change, I'm switching to 30 wt.