2005 Ford 5.4L 4V GT (SC) Oil Recommendation?

[427Z06]

Michael SR, JustinH, Geoff, I was saying the same thing months ago when the 5w20 UOAs were coming and hords of people began jumping on the 5w20 bandwagon.

Glad to see I have a few more poeple in my camp now.

 

[MNgopher]

quote:

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Originally posted by Etcetera:


Here's the question: Can I run 5-50 in a v-10 modular? Is there really any difference from the stand point of engine oil between the v-10 and the 550hp v8?

I've got a lead foot.

Thanks

Eric
La Habra, CA

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Well, I can give some real world experience. I'm running Rotella T Syn 5w40 in my 99 4.6l F150. As you know, the 4.6, 5.4, and 6.8 share many details.

On my last UOA, engine wear was up per mile for iron and copper, and down slightly for aluminum, IIRC, compared to 5w20 Havoline. This over a similar interval in terms of driving and weather.

In addition, I paid a miles per gallon penalty of 7% (yes, you read that correctly) versus runnig 5w20 or 5w30 (statistically, I get little defference between those). Obviously, this is much more than noise in the statistics.

And to those who say I'm full of it, my Jeep 4.0l showed no difference in fuel mileage between 5w30/10w30 and running the 5w40. I'm not imagining the difference. I've got no vested interest in saying thick or thin is better for fuel mileage, just reporting my results.

Long story short, 5w20 or 5w30 results in nearly identical wear with much better fuel mileage than running the 5w40. I can't imagine the 5w50 being any more fuel efficient than a 5w40 is!

That being said, I do know someone running 5w50 in a 4.6l now, but of course that truck is pushing 245,000 miles now and is used to control oil consumption...

 

[Etcetera]

Mileage is a significant issue. With 87 octane pushing $2.30 around here 7 % becomes significant. Maybe I'll switch back to MC 5w20, or maybe the new 5w30. Depends on the UOA with 0w20.

Interesting point made about oil temperature. I've never seen mine go above 220F, even while towing 11,000lbs up long grades in the California desert. This truck does have an oil cooler, maybe the ford engineers do know a bit.

I wish I could find the UOA for MC 5w20. It was the first change I did after getting the truck. That oil saw 600 miles of towing and hot weather. The numbers looked OK, and blackstone didn't have any negatives to report.

I'm not interested in extending change intervals much more than 5-6000 miles, which is about 6 months.

Eric

 

[427Z06]

quote:

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Originally posted by MNgopher:
Obviously, this is much more than noise in the statistics.

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Unless you can control many more of the variables, personally, I'd consider it statistically significant, but not accurate.

 

[T-Keith]

The GT engine is a specialy built aluminum block, and a Twin Screw supercharger not a roots. It's similiar in concept to the 5.4 truck engines, but it's oil demands and bearings are probably much different.

-T

 

[JustinH]

Sorry, I consider the twin screw blower to be a roots blower also. To me roots blower means a positive displacement supercharger that sits on top of the intake manifold.

JH

 

[JustinH]

I just wanted to get back to this thread.

The one poster compared the 5.4 GT40 engine to the 5.4 truck engine.

They are in the same family, but they are not the same animal.

The GT40 is a fully built engine with forged interals and a roots supercharger bolted on top of it.

This is apples and oranges compared to the 5.4 truck motor with stock rods/pistons. Also ford is trying to squeeze every ounce of mile per gallon out of their big trucks, so thats another reason to recommend 5w20.

I'm not saying the 5w20 is a bad oil, its not. I might consider using it in my 98 4.6 f150 (stock). Probably not though, hehe.

I'm saying that ford is not going to put a thin oil in an exotic sports car with a supercharged engine, and I don't use a thin oil in my supercharged modular engine either.

The GT40 is already a gas guzzler out of the box, so why jeopordize the motor, and possible recalls with a thin oil?

I was reading that the GT40 gets like 9 miles to the gallon a clear gas guzzler.

Man I want one so bad, I see the commercial and time seems to stop for that moment in time.

 

[Jerry]

The new 2007 5.4 SC Mustang Shelby is also 5w-50... Is it really that much diff than older 4.6/5.4L SC engines that are rated 5w-20 ?
Engine pic - not oil filler cap.

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http://www.stangsunleashed.com/index.php?categoryid=3&p17_sectionid=38&p17_imageid=408

 

[BlownF150]

The GT's motor is a whole new animal. It shares a few basic dimensions but overall it is a clean sheet build. Runs a Lysholm screw-type blower, btw...

In anycase it is a dry-sump motor and the oil passages are larger and somewhat different locations than the iron block 5.4L Triton motors. That's why it can use a thicker oil. My truck calls for a 5W-30 and that was before changed the specs to a 5W-20. Have to run a thin oil in these motors. As far as 5W-50 is concerned I don't know if it make much of a difference for regular motors. Anybody know what the 03/04 Cobras required?


There is a .pdf of a SAE article that details a lot of the GT's motor's developement that I'll post if anyone is interested.

 

[cobra3757]

The 03/04 cobras require 5w-20