What is with used Mustang GT (4.6) prices?

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ElFenix

Elite Member
Super Moderator
Mar 20, 2000
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BTW I'm surprised how unintrusive the traction control is. I have done little drifts and have yet to see the light come on. It rained yesterday and I lost traction a few times just taking off from stoplights but it never kicked in. Maybe I should find a wet parking lot and make sure it actually works

take it out today for that.
 

phucheneh

Diamond Member
Jun 30, 2012
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The TSB says to do it with the engine at room temperature!

See failed ninja edit. It's what works. YMMV, I make no guarantees, but it is an option I recommend you look into. I'm sure there are both good and bad experiences out there.

Ford's definitely never going to tell anyone to work on a hot engine. Especially not while working around skin-melting aluminum. Just like they'll never tell anyone to do any work even vaguely possibly involving anything electrical without disconnecting the battery.
 

Throckmorton

Lifer
Aug 23, 2007
16,830
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Jollyroger, should I use 5W-30 oil? Or 10W-30 since Spring will be here soon and it won't drop below 70F?
 

Sohaltang

Senior member
Apr 13, 2013
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Wow. Nice to see my stang is worth almost what I paid for it 3.5 years ago. 07 gt. I put a saleen SC on it though@8psi with all the required upgrades.
 

JoLLyRoGer

Diamond Member
Aug 24, 2000
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Jollyroger, should I use 5W-30 oil? Or 10W-30 since Spring will be here soon and it won't drop below 70F?

5w-20 is what these cars call for from the manufacturer.. There are varying opinions as to why. The motor-oil debate is a hot topic amongst s197 owners and you will find opinions on both sides of the fence for as far as the day is long.

The prevailing argument is that Ford switched to 5-20 to help CAFE ratings at the expense of greater engine wear. Makes sense... Sounds just like something those bastards would do... Several claim to have run 30w (and heavier) without issues and in fact Ford does not call for the 5-20 outside of the good ole US of A so that further bolsters the argument.

Here is my take:
On an otherwise stock motor... I think you should be running 5-20 and here is why. When Ford switched up to the 3v heads in -05 they introduced variable cam timing.. These cam phasers are very precisely controlled by oil pressure. Running a different viscosity than what is recommended has the potential to adversely effect this system so I run the 5-20. BUT.. I also run straight Mobile-1 full synthetic and nothing but genuine Motorcraft filters and change my oil often. So if you do go with what the book says I at least recommend staying off the dino oil.

I've racked up 68,000 trouble free miles so far and beyond the day to day diving, I do drive my car hard about once a month... and by hard I'm not referring to pushing it through some twisty backroads... I mean I have it out on course racing competitively asking for 10/10ths out of the car's drivetrain. So far so good... So YMMV, but that's what has worked for me.
 
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Throckmorton

Lifer
Aug 23, 2007
16,830
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5w-20 is what these cars call for from the manufacturer.. There are varying opinions as to why. The motor-oil debate is a hot topic amongst s197 owners and you will find opinions on both sides of the fence for as far as the day is long.

The prevailing argument is that Ford switched to 5-20 to help CAFE ratings at the expense of greater engine wear. Makes sense... Sounds just like something those bastards would do... Several claim to have run 30w (and heavier) without issues and in fact Ford does not call for the 5-20 outside of the good ole US of A so that further bolsters the argument.

Here is my take:
On an otherwise stock motor... I think you should be running 5-20 and here is why. When Ford switched up to the 3v heads in -05 they introduced variable cam timing.. These cam phasers are very precisely controlled by oil pressure. Running a different viscosity than what is recommended has the potential to adversely effect this system so I run the 5-20. BUT.. I also run straight Mobile-1 full synthetic and nothing but genuine Motorcraft filters and change my oil often. So if you do go with what the book says I at least recommend staying off the dino oil.

I've racked up 68,000 trouble free miles so far and beyond the day to day diving, I do drive my car hard about once a month... and by hard I'm not referring to pushing it through some twisty backroads... I mean I have it out on course racing competitively asking for 10/10ths out of the car's drivetrain. So far so good... So YMMV, but that's what has worked for me.


That is exactly the info I've been looking for and wasn't able to find. For example people talk about how Ford switched the oil from 30 to 20 at one point without changes to the engine, but they don't mention what changes ocurred AFTER. So now I know about the cam phasers. They also say that in Australia the 4.6L engine requires 5W-30... but the Mustang isn't sold in Australia and I see no reason to believe the engines in Falcons are identical. I have yet to see a mention of oil requirements in Canada or Mexico.

I'll stick with 5W-20 and switch to Mobil 1. As I understand, mineral oil thins with use, while synthetic stays the same, so synthetic 5W-20 might protect as well as old mineral 5W-30.
 

phucheneh

Diamond Member
Jun 30, 2012
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'Cam phaser' usually refers to a camshaft position sensor (CMP). In particular, Ford engines where they just removed the distributor, and replaced it with the lower half of one (shaft/gear part) with a cam sensor on top.

He's talking about solenoids and associated oil passages that control the VVT. It makes the engine more sensitive to sludge or debris in the oil, but a higher viscosity should not have an effect...varying oil pressure is expected. Running 5w30 instead of 5w20 would just be akin to the engine oil temp being lower (more viscosity/oil pressure).
 

Fern

Elite Member
Sep 30, 2003
26,907
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That is exactly the info I've been looking for and wasn't able to find. For example people talk about how Ford switched the oil from 30 to 20 at one point without changes to the engine, but they don't mention what changes ocurred AFTER.
-snip-

There's a bunch of info on this at various stang forums.

The above poster is correct, the switch was made for CAFE purposes.

From what I've read:

1. Use the 5-20 if your not doing heavy mods and racing.

2. The FRD (Ford Racing Development) side has 'officially' recommended 5-30 for those with mods/racing.

3. If your vehicle has +100k miles use 5-30 for better protection for older/worn engines. persumably, after a rebuild and new bearings etc you can go back to 5-20.

Fern
 

JoLLyRoGer

Diamond Member
Aug 24, 2000
4,154
4
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'Cam phaser' usually refers to a camshaft position sensor (CMP). In particular, Ford engines where they just removed the distributor, and replaced it with the lower half of one (shaft/gear part) with a cam sensor on top.

He's talking about solenoids and associated oil passages that control the VVT. It makes the engine more sensitive to sludge or debris in the oil, but a higher viscosity should not have an effect...varying oil pressure is expected. Running 5w30 instead of 5w20 would just be akin to the engine oil temp being lower (more viscosity/oil pressure).

Mmmm sort of but not quite...

Remember, we're talking overhead cams here.

The engine actually uses a pulse ring and a pickup sensor that sits behind the crankshaft pulley to determine crank position. The crank sensor is located to the right (passenger side) of the crankshaft pulley down next to the belt tensioner pulley.

Then there are two camshaft position sensors installed in the front cover that sit well.. right near each of the camshaft phasers. The computer uses these inputs to adjust valve timing on the fly.

The camshaft phasers (in the context of the 4.6L 3v) are actually part of the sprocket that the timing chain goes around but they can also advance or retard the cams up to 60 degrees of movement in relation to the crankshaft. And yes, ultimately they are solenoid controlled.

In fact, the phasers can adjust cam position so much that a lot of guys run into trouble when they move to bigger cams so you'll hear a lot of people talking about running 20 degree phase limiters or phaser lockouts which basically amount to a mechanical stop to prevent the phasers from rotating so much.

634-794-216862.jpg


vvt-system.jpg
 
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Throckmorton

Lifer
Aug 23, 2007
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If Ford SVT recommends 5W-30 though for modified engines, I should be fine using it right? The only thing I lose is a tiny amount of miles per gallon? Surely it wouldn't cause cam phasing issues if it's what Ford themselves recommend.
 

exdeath

Lifer
Jan 29, 2004
13,679
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You're thinking too hard on this 5w20 vs 5w30 thing, you won't notice a thing. Its not like you're putting in 75w140...
 

Throckmorton

Lifer
Aug 23, 2007
16,830
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I drove to Dallas on the weekend and the car is great on the highway. The Magnaflows are a little noisy on the highway at 70-80mph so I'd prefer the stock exhaust for cruising... but on the other hand sometimes I like to listen to the V8 purring. It's still a lot quieter than the E36 because it had so much wind noise (what about the Autobahn??).

On the way back I took the state highways because it was late and I didn't want to fall asleep on the boring Interstate 45. It's kind of crazy how the speed limits on those 2 lane curvy roads in Texas is 70mph. In a lot of spots I dropped down to 60 because the surfaces weren't that good and because of the blind curves. I almost hit a deer and a rabbit.... This car really needs better headlights. I don't like the color of HIDs though so I'm thinking about modding 5.75" e-code headlights into the foglight housings for twice the light (but no more retina burning brightness). I just need to find buckets with adjustment screws.

I did get to feel the solid axle on a Dallas onramp. I was already at merging speed and and joint in the concrete upset the rear.
 
May 13, 2009
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Well if I can have more protection and no downside, I'd rather use the 5W-30

Is there actual evidence that one provides better protection than the other. I had a bike once and the forums specific to that model preached about running a certain oil so I tried it. We'll it wasn't long after that my engine developed a tick. Might have been a coincidence. Either way I will stick with the manufacturer specs from now on.
 

Throckmorton

Lifer
Aug 23, 2007
16,830
3
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Is there actual evidence that one provides better protection than the other. I had a bike once and the forums specific to that model preached about running a certain oil so I tried it. We'll it wasn't long after that my engine developed a tick. Might have been a coincidence. Either way I will stick with the manufacturer specs from now on.

I've been searching and there seems to be no info aside from Ford's CAFE influenced recommendation and that engineer named Scott http://corner-carvers.com/forums/showthread.php?t=36607&page=3

No one seems to have done oil analyses to compare the different weights. No one can really explain why a thicker oil is worse. People just post vague stuff about what they've seen happen with OTHER engines. The Mustang community is really disappointing me. If it was a BMW there would be a lot of knowledgeable posts and detailed discussion of actual pros and cons of the different weights. All I've seen is Jollyroger posting here about the cam phasers. That former Ford engineer said that it might affect the cam phasers, but he is vague about everything he says. He said that "a 5W-30 oil is probably good for the street". "Probably"? You fucking created these engines and the best you can say is "probably"?
 

Throckmorton

Lifer
Aug 23, 2007
16,830
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The Boss 302 uses 10W-50. Can one person just tell us whether that engine has different bearings/cam phasers/pumps/galleys/whatevers from the 4.6L that allow it to use a thicker oil? Or are they the same aside from displacement? I've seen multiple instances of folks on the Mustang forums quoting the the recommendations for those engines, but without stating whether there are any differences.
 
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jlee

Lifer
Sep 12, 2001
48,511
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Oil weight should be whatever you need to produce ideal oil pressure. Typically that's about 10psi per thousand RPM. One of the local MR2 guys was making ~55psi at 6500rpm, so I recommended that he switch to a 5w40. His pressure is now up in a safer range.
 

Throckmorton

Lifer
Aug 23, 2007
16,830
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Oil weight should be whatever you need to produce ideal oil pressure. Typically that's about 10psi per thousand RPM. One of the local MR2 guys was making ~55psi at 6500rpm, so I recommended that he switch to a 5w40. His pressure is now up in a safer range.

But what about the other factors like wear protection, the amount that gets pumped, lifespan of the pump, how quickly oil gets into bearings, etc?
 

Throckmorton

Lifer
Aug 23, 2007
16,830
3
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BTW I noticed the V6 4.0L uses 5W-30. If it was really just for CAFE purposes, wouldn't Ford have switched taht engine to 5W-20 also? Especially since most Mustangs are V6? Hmmm.... maybe there is some difference in tolerances, or valves, or something. But maybe the V6 would get better protection with 5W-40
 
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JCH13

Diamond Member
Sep 14, 2010
4,981
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But what about the other factors like wear protection, the amount that gets pumped, lifespan of the pump, how quickly oil gets into bearings, etc?


I believe you're REALLY over-thinking this. That statement comes from an engineer who gets paid to over-think.

None of us have instrumented engine stands in a climate controlled test room with your particular engine on it, therefore none of us can answer your question. I believe no one else can definitively answer them either besides an in-the-know engine engineer at Ford.

As a pracitical solution: try an oil, get a UAO, see what the experts say. If you don't like the results, try a different oil and get another UAO. They will be able to detect engine wear products in the analysis and you can pick which ever oil makes you the happiest. Then you can be the one on the Ford Mustang forums who has real data for a real answer. Step up!
 

JCH13

Diamond Member
Sep 14, 2010
4,981
66
91
BTW I noticed the V6 4.0L uses 5W-30. If it was really just for CAFE purposes, wouldn't Ford have switched taht engine to 5W-20 also? Especially since most Mustangs are V6? Hmmm.... maybe there is some difference in tolerances, or valves, or something.

I believe those are engines from entirely different generations and applications, no?