Ford 4.6L DOHC oil opinions - it's been discussed

69GTX

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Originally Posted By: tig1
If the subject here is about excess engine wear with 20 wt oils then the UOAs don't show that. With the millions of engines using 20 wt oils, why don't we hear of mass engine failures over the last 15 years. This appears to be another "thick vs thin" post. Notice the UOA section on page 1 of the Merc GM 4.6 UOA using 5-20.
The post is on what I found among various blogs on this topic...and those invariabily turn into thick vs. thin posts. What would answer the question is finding out of those engines over 15 years that used one weight or the other, which generally had a higher % wear and/or failure rate. It might only be a 45-55% or 40-60% split to one side. But, without mass tear downs, we'll never know as it doesn't benefit anyone to spend the considerable $$ find it out. We're not looking for mass failures....only which method works significantly better than the other. And 45/55 would be significant....just like in elections.
 

CT8

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Personally I don't understand where people get the idea that running a heavier grade oil will ruin a 0-5W-20 spec engine. 30w + will increase the time before failure under extreme hard use if the engine gets to that point. Everything on a modern vehicle is CAFE driven.
 
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The company I work for runs a fleet of modulars, mostly 6.8L 2v engines. They're on loaded F350/F450's, thus they see their fair share of abuse. They've used every oil weight under the sun, yet they run forever and never break down. The first mechanic was an old-timer that swore by 10w40 and his reasoning for the OEM suggesting 5w-20, is that the truck is built in Michigan where it's cold. News to me, as the trucks are actually made in Kentucky. That mechanic is gone now, so the operators usually pick the oil weight now. Lately it's been 5w-20, and the engines just don't care. Personally, I think if you value the utmost in fuel economy and efficiency, run 5w-20. If you want to go the distance and drive the darn thing to 300k, I think a heavier weight would be beneficial toward longevity. I like HDEO oils myself, and if I owned a truck with this engine, I'd use a 10w-30 HDEO like Chevron Delo XLE. Or Motorcraft. Or Shell Rotella....
 
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Originally Posted By: Ramblejam
Originally Posted By: ShotGun429
We build alot of hi-po mod motors here, On the Dyno at full song a engines life can be measured in minutes using 5w20 hours with 5w30. and with 15w-40 we can leave it running in the test cell and take off for the weekend and that Mod is running perfect Monday morning, Do i dare to say those light oils are "CAFE Driven"
...and there are V10's in medium-duty applications (class 4-6) that see "full song" use on a daily basis with 5w-20 in the sump, yet last for 250k+. As you said 69GTX, "it's been discussed." Xw-20 in these applications isn't a new thing, and we have many years now of real-world data/observation to go on when making a decision. For a stock engine in normal street usage, the OEM recommendation is appropriate.
+1 My fathers companies V10 is used to tow large trailers only.... 5w20 and 200k miles later it doesn't use oil, has excellent compression. It runs at 4-6k RPM most of the time. 5w20 is NOT too thin.
 
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In the quad cam 4.6 I will say that from everything I remember reading while I owned a 99 and 03 cobra, I believe in running 7 quarts. Somewhere floating around is a guy showing the capacity of the pan and how much oil you would have to add to run into windage issues. 7 was safe, I think the conclusion was you could get away with running up to 9 quarts in the stock pan. Adding another quart brings the level up just a little. This idea came about because there were a concerning amount of owners eating bearings in the N/A Cobras way back when. The N/A cobras had higher redlines. The failures suggested the pumps were sucking dry because the oil wasn't making it back down from those giant heads fast enough.
 
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I've ran 0w-20, 5w-20, and more recently 5w-30 in my 2005 F150 5.4. It's noticeably quieter with 5w30. I haven't noticed any diminished performance or fuel mileage. I'm going to stick with 30 weight from now on, truck has 130k on it.
 
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Originally Posted By: Garak
Note that an ILSAC 20 and an ILSAC 30 are basically two data points staring at each other from either side of a very narrow line.
So it's not a "thick/thin thread" as these types of conversations are continually labelled but a "thin/thinner" ??? LOL
 

69GTX

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Originally Posted By: Shannow
Originally Posted By: Garak
Note that an ILSAC 20 and an ILSAC 30 are basically two data points staring at each other from either side of a very narrow line.
So it's not a "thick/thin thread" as these types of conversations are continually labelled but a "thin/thinner" ??? LOL
Well it did start out as a "thin / thicker" thread. The one thing I was looking for more information on was using a 0/5w-40 grade in my next summer time OCI.
 
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Originally Posted By: Shannow
So it's not a "thick/thin thread" as these types of conversations are continually labelled but a "thin/thinner" ???
Yes. How else can I get a dig on ILSAC 30s? wink ILSAC 30s are hardly my idea of an oppressively thick, power and fuel sapping grade. Granted, I don't have a lot of use for or patience with a 10w-XX or a 20w-XX, but having good winter performance doesn't require running an ILSAC 20, either.
Originally Posted By: 69GTX
The one thing I was looking for more information on was using a 0/5w-40 grade in my next summer time OCI.
As you can see, I certainly have no problem with using such an option as a year round fill. Reading some other threads reminded me of how lucky we are in this part of the world when it comes to A3/B4 options. While we don't get much in the way of 10w-40 A3/B4 options, or cheaper A3/B4 options (the North American thick, cheap oil is HDEO), if you see an A3/B4 oil here, you can be rest assured it's going to have a nice, low number before the "W" for year round use. Note that my G37 has variable valve timing and all those goodies, and I've never come across any concern anywhere about that system having difficulty functioning outside some narrow and hard to attain viscosity window. 5w-30 ILSAC is recommended here, but 5w-30 non-ILSAC (i.e. C3) is permissible, so there's a pretty wide range of viscosity options, particularly with A3/B4 being specified in other locales.
 
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