Mattr89
Cars>Woman
I may change back next oil change still not a 100% sure yet.
No. You will be just fine with 5w30. My own experience with it is an increase in valvetrain noise.
I use valvoline VR1, has lots of zinc for less than $5 a quart....10w30
The clearance information is available in the specifications section of the 4.6 3v manual for the Mustang.
http://iihs.net/fsm/?dir=158&viewfile=SPECIFICATIONS.pdf
Is Scott Whitehead a disgruntled former Ford employee? Has he ever been contridicted by other Ford engineers?
Think about it for a moment: More wear would cause more drag. Your theory that 5w20 will cause both more effiency and more wear contridict each other.
Can you tell me how much force will be required to push 5w20 oil through the oil galley? How much to get it up to the heads and properly lubricate the valvetrain? How much flow is required to effectively lubricate and cool those parts? Pressure and flow have an inverse relation to each other. The oil in a 3v flows from the pickup to the filter to the pump and out through the block getting to the valvetrain last.
I don't have the answers to those questions. It would take quite abit of research, education, prior data, and equipment to determine the optimal blend. Ford has done the research with stock motors.
I can understand wanting to use the best for your engine. I can't understand using something because of a conspiracy theory.
What are you going to spec clearances at on the motor you are about to build?
Edit: Adding answer to another post.
No. You will be just fine with 5w30. My own experience with it is an increase in valvetrain noise.
that is my experience also. I changed from Mobil1 5W-20 to Shell 5W-30 and had a lot more cold valvetrain noise. I changed it at 4k miles and it was very black as well. I went back to Mobil1 5W-20 and the noise went away. I live in GA and thought the heavier oil would be OK since we have milder winters here...
I think you will be OK, I just didn't like the ticking/rattling when it was cold!
that is my experience also. I changed from Mobil1 5W-20 to Shell 5W-30 and had a lot more cold valvetrain noise. I changed it at 4k miles and it was very black as well. I went back to Mobil1 5W-20 and the noise went away. I live in GA and thought the heavier oil would be OK since we have milder winters here...
I think you will be OK, I just didn't like the ticking/rattling when it was cold!

if i was to say my most hated list, here it is.
Top 5 WORST oils (1 is worst)
1.Penzoil - complete utter garbage! I had 2 different engines blow with this oil
2.Quaker State - Just as bad as penzoil but never had an engine blow
3.Castrol - look this one up. they are the reason for 3k oil changes! Their oil broke down before 3k, they started the whole every 3k change!
4.Mobil1 - burns oil in EVERY single car i have ever used it in! I speak from over 12 years mechanic experience!
5.super-tech - walmart brand oil is far superiour to the above oils, in every way! Never had an issue with it, however not good for performance cars.
Best oil:
1.Royal Purple - This oil has been my single choice since 2002. Its NEVER let me down! In fact there was a time with one of my cars 6 years ago where i had a cracked piston and blown ring, and the car was making power and running for over 20k with royal purple! One day i ran mobil 1 because there was no royal purple left and the engine threw 4 rod bearings!! i pulled it apart to find that the piston was cracked and had been for some time, as well has blown ring. Royal purple saved the engine life!
Royal purple literally has 4 times the film strength than mobil 1 or amsoil! Proven fact. great oil.
Your problem was using crap Shell oil, it had nothing to do with the minute difference in viscosity between 5w-20 and 5w-30.
Shell Rotella oil is also the worst possible oil you can put in a diesel motor, pure crap that loses viscosity in less than 200 hours.
I run 10w40 year round in virginia no problem. 5w30 is perfectly fine.
I use valvoline VR1, has lots of zinc for less than $5 a quart....10w30
That's what I use in mine as well. Zinc and phosphorus are very good for bearings but hardly any oils contain much of it because they will both clog cats. That's why it is a "racing"" oil.
More pressure = less flow. Pressure is a measure of force and restriction. Oil flow has to be maintained for cooling and a wedge. It's a delicate balance. The oil also has to make it to the heads to lubricate and act as a hydraulic fluid for the valvetrain.
BTW this is a forum dedicated to the S197 platform. That's why I quoted minimum specs for a 3v.
Here's a few samples from the first motor I built.
Virgin RP 5w-20
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This is the first run with RP. The motor was broken in with conventional oil.
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It was after this analysis that I decided the whole oil geek thing is not for me. As long as I'm running API certified oil in a viscosity that works for my motor I'll be alright. I've tried 0w-30 and 5w-30 but both increased valvetrain noise. Valvetrain failure has been documented on this site. The why is undetermined. Could be bad parts. To me more noise = more chance of failure.
Everyone on this site has reasons for what they use and I don't wish bad juju on anyone.
I want the oil that will flow as much volume as possible while maintaining pressure and a wedge.
I don't buy into the "sky is falling 5w-20 is a government sponsored attack on car owners" mentality. If you want to it's your business. I think it's pure bullshit.
This.So you put mobil1 one time and you threw 4 rod bearings, cracked a piston and a blown ring?
The problem with lubrication is that there is a lot of hearsay going around. The only 100% sure way to know if the oil you selected is working adecuately is by doing an oil analysis. Its only like 12 bucks and takes out the guess work...
Afterwards if you continue with your recommendation all will be great.
http://fordtruckworld.tenmagazines.com/visit.asp?http://www.dantheoilman.com/modular.xlsPlease take the time to read some of the information please. It is ok having a product that meets API certified levels but why not having one that beats the min by a million...On the other hand is there any other data that 5w-20 performs better other than "thats what the sticker says"?
As far as the CAFE standards... you do know that all FORD v8 engines sold in the us that require 5w-20; in australia where there are NO cafe standards, the SAME engine requires 5w-30. This includes the 4.6 3v s197 again please take the time to read some of the links I posted. Afterwards if you continue with your recommendation all will be great.
I don't recall recommending anything. It would be foolhardy to do so imo. I have given my reasoning for my choices, tight clearances. I kept the Ford clearances in my motor in part because of vct and the stock georotors and pressure relief spring in my oil pump. I don't want to trigger the pressure relief valve or put too much stress on the georotors.
Most of the people on this forum do not have cookie cutter motors and other things have to be accounted for. I know most turbo guys go with a 10w-x because keeping the turbo cool is a priority and they generate alot of heat. Others have clearances specific for the application, etc.