CAMMED and tuned - oil questions

theRedStorm

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I have a 2005 Mustang Gt with roughly 85k miles on it. I put cams on about a year ago. I noticed my car now burns 1 to 1.5 quarts of oil now between 4k mile oil changes. Before cams, it burned about half a quart to 1
I currently use 5w20 Ford Motorcraft

So I am thinking of upgrading to Royal purple HMX. Now the only thing I'm wondering is, would it be a better idea to use 5w30 or 5w40? I know the car is heavily modified so heavier oil will definitely be helpful in preventing wear. Is this safe for VVT? Any other recommendations as well?
 

Juice

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I run Mobil1. I have run 5w50 and 0w40. No issues with VCT or otherwise.
I would recommend 10w30 M1.
I dont buy the RP hype. Its a boutique oil and you overpay for that. Same with Amsoil. I have run both. Now its Mobil from wally world in the 5qt jugs.
 

Laga

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I run whatever 0W-20 is on special. Any 0W-XX oil will have the highest content of full synthetic oil. Only full synthetic oils will meet the flow criteria of a 0W oil.
 

GlassTop09

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I run whatever 0W-20 is on special. Any 0W-XX oil will have the highest content of full synthetic oil. Only full synthetic oils will meet the flow criteria of a 0W oil.
Hi Laga,
May I ask why do you use a 0W-xx motor oil? How cold does it get where you live?

I run MC Full Synthetic 5W-30 in my car w\o issue & lose less than 1\4 qt over 5,000 mi (I'm not FI & just recently noted during plug changeout I have a valve stem seal on 1 of the 2 intake valves in #3 cylinder leaking slightly @ 152,895 mi so this explains that...have an ADD W1 v3 Catch Can installed & have less than a 1/4" of oil captured over a year's time...PCV valve verified working & FRPP Intake Manifold verified clean when pulled last month checking for vacuum leaks).

Just curious...……………..…….
 

TANN3R_

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I´m running on several different 5w-40 in past two year and don´t see any different against 5w-20. No VVT issues at all.
I take 5w-40 only because in europe we do not have much of 5w-20 or 5w-30 without low saps norm (which is bad in my opinion).

Now I found Millers Oils Trident 5w-30 which have very good specs, include HTHS 3.65 mPa.s so I´m going to try this oil next.
 

Dino Dino Bambino

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I'm in Europe and I run Castrol Magnatec 5W-20. There's no advantage to running a thicker oil unless:

1. The engine has significant wear with increased rod and main bearing clearances causing a reduction in oil pressure especially at hot idle and low rpm.

2. You run the car hard for prolonged periods on a road course where the engine oil temperatures are raised above the levels expected in normal street driving. In such a case you could add an aftermarket oil cooler.
 

Laga

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Hi Laga,
May I ask why do you use a 0W-xx motor oil? How cold does it get where you live?

I run MC Full Synthetic 5W-30 in my car w\o issue & lose less than 1\4 qt over 5,000 mi (I'm not FI & just recently noted during plug changeout I have a valve stem seal on 1 of the 2 intake valves in #3 cylinder leaking slightly @ 152,895 mi so this explains that...have an ADD W1 v3 Catch Can installed & have less than a 1/4" of oil captured over a year's time...PCV valve verified working & FRPP Intake Manifold verified clean when pulled last month checking for vacuum leaks).

Just curious...……………..…….
As stated, in order to achieve the 0W classification, the oil has to flow at a certain rate at -35°C. Only oils with large percentages of full synthetic can achieve this as conventional oils will thicken too much.
This is how oil behaves. It thickens as it gets cold and thins as it gets hot. So a 0W-XX oil will be many times thicker at most startups than even a 30W or 40W oil at operating temperature, 100°C. Synthetic oils have been proven to flow better at all temps below 100°C, so this reduces wear at startup. There really is no reason not to run a 0W-XX oil.
Dino is correct. Unless there is a problem with the engine, or it is raced for prolonged periods of time, there is no benefit to running a thicker oil than recommended.
Technically, there is no benefit to run any oil other than what the car requires. Even cheapo oil that carries an “SN+” rating, and correct viscosity, will protect the engine properly if changed at the correct interval. And that can only be truly determined by doing a used oil analysis.
 

TANN3R_

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Here are some of my observations:
- Clearances on main bearing, rod bearing and camshaft are basically same on 4.6 3V like GT500 have and there is recommended 5w-50. In my opinion it is because higher loads are assumed.
- Clearance tolerance on base V6 are very close to 4.6 and Ford recommended 5w-30
- In Australia Ford recommended 5w-30 for the same 4.6 3V in stang.

Only my opinion - Ford agreed to reduce the class to 5w-20 mainly due to CAFE regulations.
 

eighty6gt

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all true, my rod clearances are on the big side so I run 2 quarts 5w50 and the rest cheap ass mobil 5w20. Who knows what it's doing in there but the brearings aren't all out in the pan so .. ok!
 

Laga

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Here are some of my observations:
- Clearances on main bearing, rod bearing and camshaft are basically same on 4.6 3V like GT500 have and there is recommended 5w-50. In my opinion it is because higher loads are assumed.
- Clearance tolerance on base V6 are very close to 4.6 and Ford recommended 5w-30
- In Australia Ford recommended 5w-30 for the same 4.6 3V in stang.

Only my opinion - Ford agreed to reduce the class to 5w-20 mainly due to CAFE regulations.
And yet millions of 4.6 engines have logged billions of miles with few oil related problems.
 

Midlife Crises

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Another reason to run a heavier weight oil is the additional cylinder wall clearance when using forged pistons. Add the higher forces on the rod bearings from FI and different oil spec.for the GT 500 makes sense.
 

RED09GT

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As soon as a set of 2618 forged pistons is up to operating temperature, the piston to wall clearance is no different than the stock hypereutectics. I run 5w20 on my motor (stock spec bearing clearances) with .0035" PTW clearance, which is on the tighter side for diamond 2618 pistons.
I do get a lot of oil coming out of the breathers so I'll try a slightly thicker oil if my latest catch can/ breather scheme doesn't work out.
 
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Norm Peterson

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And yet millions of 4.6 engines have logged billions of miles with few oil related problems.
2008 Mustang Owner Manual said:
SAE 5W-20 oil provides optimum fuel economy and durability
performance meeting all requirements for your vehicle’s engine.
What that says is that it's primarily for optimizing fuel economy (like with lists of product ingredients, the first thing mentioned is the main ingredient/reason).

But it only meets durability requirements for a stock engine. That doesn't necessarily mean that it exceeds the requirements for stock engines by much, and says nothing about what Ford would consider "abuse" rather than "normal driving".


5W30 Motorcraft full-synthetic here, for both street and track use. Stockish engine, on true street tires; R-compound or higher tires would probably call for something like 40 or 50 hot weight.


Norm
 
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MrAwesome987

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I run 5w-30 in mine. It sucks a good bit through the catch can, but haven't had any problems other than that.
 

Midlife Crises

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As soon as a set of 2618 forged pistons is up to operating temperature, the piston to wall clearance is no different than the stock hypereutectics. I run 5w20 on my motor (stock spec bearing clearances) with .0035" PTW clearance, which is on the tighter side for diamond 2618 pistons.
I do get a lot of oil coming out of the breathers so I'll try a slightly thicker oil if my latest catch can/ breather scheme doesn't work out.
I’m not sure that’s entirely true. Forged and cast pistons are shaped differently. The top land will have more clearance on a blower piston to allow for the occasional extreme while the skirt and body will be nice and snug at normal operating temperature. I set my Weiscos up at .003” total clearance. I have been running Mobile 1 10W30 and I have no measurable oil loss in 2500 miles. My intake track is also oil free.
 

RED09GT

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I’m not sure that’s entirely true. Forged and cast pistons are shaped differently. The top land will have more clearance on a blower piston to allow for the occasional extreme while the skirt and body will be nice and snug at normal operating temperature. I set my Weiscos up at .003” total clearance. I have been running Mobile 1 10W30 and I have no measurable oil loss in 2500 miles. My intake track is also oil free.
A 4032 forged piston (like the Mahle GT500's) have a stock spec is 0.0015" PTW clearance on those cars. The silicon content in the 4032's is similar to the content of a hypereutectic so the thermal expansion is considerably lower and it is easier to reach cold start emission standards.

The GT500 is a lot more prone to heatsoak than a stock GT so that is probably the reason for the different oil spec. What I take away from all this is that you can run a fairly large range of rated oil viscosities and it will protect the engine just fine. Don't stress too much about it, make your regular oil changes and use whatever you like.
 
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Midlife Crises

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I agree. A fairly wide range of quality oils should protect these engines just fine. How the car is warmed up, driven and if heat soak is even dealt with could determine the best viscosity.
 

TANN3R_

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...What I take away from all this is that you can run a fairly large range of rated oil viscosities and it will protect the engine just fine...

I totally agree.

For me is here only one negative aspect of running thicker oil and it is little worse fuel economy. But for me is more important the engine protection, so 5w-30 is ideal compromise.
 
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Pentalab

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I use RP 5W-30 HPS....since I get it wholesale. M90 blower + catch can on my 2010 auto.
Uses zero oil between changes..which is just once per year these days. I collect very little in the catch can. When 1st bought the car, I used Ford 5W-20 semi synthetic. Catch can was almost full to top....and looked like a chocolate milkshake... every 6 months.

I believe it was Bruce H who mentioned not using 5W-40 or 5W-50 in oem 4.6L engs.
 

GlassTop09

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What that says is that it's primarily for optimizing fuel economy (like with lists of product ingredients, the first thing mentioned is the main ingredient/reason).

But it only meets durability requirements for a stock engine. That doesn't necessarily mean that it exceeds the requirements for stock engines by much, and says nothing about what Ford would consider "abuse" rather than "normal driving".


5W30 Motorcraft full-synthetic here, for both street and track use. Stockish engine, on true street tires; R-compound or higher tires would probably call for something like 40 or 50 hot weight.


Norm
+1 here...….this is the issue w\ using published statistical data w\o identifying the actual determining criteria used to substantiate the results. Statistical Science 101...… All the 4.6L class Modular engines Ford produced were not all OEM spec'd for 5W-20 blend oil as those statistics also include 2V's which were OEM spec'd for 5W-30 oil...…. The min 5W-20 blend spec is specific to the 3V version of 4.6L engines in North America.

Thanks Norm for posting...…………………. I also was looking at that exact page (page 253) in the owner's manual as well & the fact that Ford printed part of that clip in bold lettering is proof of what Ford's main intentions were as well...as you've already laid out.
Any oil that will reduce rotational friction will also increase durability under similar operating conditions due to less wear so as long as the oil being used is 100% synthetic the lubrication qualities will be much improved over anything less than 100% & as long as the oil cushion\film can be maintained between the metal moving parts the engine's durability can be maintained\improved....also under similar operating conditions. Hhhmmm…..I might check on what type of oil Ford ran in the FR500C race cars....that info would be a tell IMHO......

All I know is that when I got my car the 1st oil change was done using the OEM spec MC 5W-20 blend oil (50% synthetic, 50% dino w\ 139,733 mi on the clock) then when I switched to use the MC 5W-30 Full Synthetic oil on the 2nd oil change 6 months later (had less than 2,000 actual mi on 5W-20 oil) as a test I could instantly detect a noticeable difference in how the car sounded upon the initial startup (much quieter & smoother sounding) after servicing which sold me right then & there. Been using MC 5W-30 Full Synthetic oil in her ever since...………….
 
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