The Great Oil Debate

Wraith

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I feel like I'm running in circles between Jermey and Greg [emoji857]


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nyuk98GT

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Wraith:

Amsoil fan boy here with some free advice. Check with the Amsoil chaps for even better advice.

MT-82: Amsoil MTG (75W-90) if you live in an area where the ambient temperature does not get below 50 F very often (and where the ambient temperature is "hot" in the summer months). You will get a 'nibble' on the 1-2 shift in cold temperatures (<50 F). I got around the nibble by starting off in 2nd gear. After a month of that, I decided to switch to MTF (see next bit).

MT-82: Amsoil MTF Syncromesh (5W-30) for just about all climates. The MTG (75W-90) will quiet any whining from the transmission and the MTF will reduce the 'nibble' to almost zero in cold temperatures. The shifts were butter-smooth with MTG but the first minute of driving had to be very gentle to avoid a shift nibble. For the record, I have not noticed any whining after switching from MTG to MTF.

Don't be fooled by the 75W-90 and 5W-30 designations being wildly different viscosities because they are, in fact, pretty similar.

I would ask the Amsoil gurus if Motorcraft XL-18 additive is recommended for MTF or MTG in the MT-82. I haven't added it yet (I've only had the MTF in use for a couple of weeks) but I might add it in the future. So far, the MTF is working very nicely even in the recent cold morning temperatures (mid-20's F) in eastern Missouri.

Differential: Amsoil Gear Oil 75W-140 plus Motorcraft friction modifier or the Amsoil version.

If you have an aftermarket diff cover with a fill hole then you should know that the fill hole on the back of the differential (it faces the front of the car) is the one that MUST be used to avoid overfilling the differential. Trust me, lol.

HTH,

Chris
 

Pentalab

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If you are using something like an eaton tru-trac differential, dino oil is used, no synthetic, and no friction modifiers.

RP synthetic differential oil comes with the friction modifier. I don't know anybody who has used it, so can't comment on it.
 

Sky Render

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If you are using something like an eaton tru-trac differential, dino oil is used, no synthetic, and no friction modifiers.

RP synthetic differential oil comes with the friction modifier. I don't know anybody who has used it, so can't comment on it.
Came here to say this. I use Lucas Oil 75-W90 with no friction modifier in my TrueTrac. Using synthetic oil and/or friction modifier in a worm gear diff actually lowers the bias ratio.

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Pentalab

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Came here to say this. I use Lucas Oil 75-W90 with no friction modifier in my TrueTrac. Using synthetic oil and/or friction modifier in a worm gear diff actually lowers the bias ratio.

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Agreed, I use the same lucas 75W-90 for my tru-trac. They require dino oil, since they rely on friction to operate. Synthetic would just lower the bias ratio way down. I think the same thing applies to a Torsen.
 

Wraith

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I intend to run stock diff and tranny for a while maybe eventually maybe gt500 tranny and 3:73 but that's hopefully a ways off. So in the end best stock replacement stuff for the money for a location which sees humid highs in 80's and winters in 30s.

Thanks


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NA-Stang

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5.0L oil question

Now, before I get roasted, I searched for this topic, but couldn't find a definitive answer.

Just changed the oil for the first time in my 2011 GT. I mentioned to a friend, who is also a mustang enthusiast, that I used Castrol gtx non synthetic oil. It's what i have used in all my mustangs, including my last 3v mustang.

He made the statement that he believes that the coyote motors require using synthetic oil. I looked in the manual, and in one section, all it says is to use 5w20 with the api certification, which of course the GTX has. However, in another section, it states that synthetic is recommended. But I looked back in my 2005 manual, and it says the exact same thing. I have never had an issue before, and I occasionally track my cars and beat the snot out of them, but not on a regular basis. I'm lucky if I get there once a month.

The coyote has bolt ons only, no FI, if this is a factor as well.

Any input on this subject? Am I making a mistake running nonsynthetic oil? Hurting the engine? Hell, God only knows what the previous owner ran in it.

Thanks in advance.
 

07TGGT

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Recommended, its just that, recommended not required. Your friend is wrong. As long as you change the oil when it NEEDs to be changed, a Coyote will run forever and not care if it's synthetic or dinosaur oil.
 

NA-Stang

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Oil? It gets a freaking sticky.

http://www.s197forum.com/forum/showthread.php?t=81441

Do 3V headers get a sticky? Fuck no!

So funny, every thread I read about oil refers me to that thread. Admittedly I didn't read all 11 pages, but the whole first page seamed to be about transmission oil. So I just figured that is where it was going to head the next ten.

Anyway thanks 07TGGT, It's pretty much what I gathered. Just wanted to make certain I didn't miss any important info on it anywhere here on the forum or on the internet anywhere.
 

Pentalab

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100% synthetic oil is relatively cheap, handles way higher temps, and last longer, so why not use it. Mobil-1 etc, is cheap in the large containers, you can buy it anywhere, walmart etc. .

BTW, the 'semi synthetic' oil is only 2-5% synthetic..and 95-98% dyno oil.

Don't forget to change the oil filter. Use a real one like the oem ford filter, or the FRPP one.. The FRPP oil filter weighs 50% more, and has 60% more media inside. same dimensions.
 

stkjock

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the issue could come up "if" you ever have a engine warranty issue. It's possible that they could ask you to prove regular oil changes and then see you used a oil not spec'd for the motor.

IMO, synth is worth the cost, it lasts longer and should give you better gas mileage.
 

05gtowner

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the issue could come up "if" you ever have a engine warranty issue. It's possible that they could ask you to prove regular oil changes and then see you used a oil not spec'd for the motor.

IMO, synth is worth the cost, it lasts longer and should give you better gas mileage.

^^ THIS^^I know for a FACT that Ford (or any warranty co.) will ask for proof of maint. such as oil changes and receipts of those oil changes. Especially if you have the Ford ESP. If the oil and filter is not what is recommended or the equivalent they will deny the warranty claim. I was using amsoil 5w-20 and amsoil filter when the original motor in my 05 let go. They tried telling me that the filter was basically not as good as the FL820S and the oil looked "thick" when they drained it. If you have a warranty, save every receipt of service, fluid and repair done, as well as dates and who did it.

If you don't have to worry about a warranty then run whatever you want be it dino or syn. Just change it every 3K and you are fine. I like the Pennzoil Platinum with a Motorcraft filter. Cheap, full syn, made from natural gas so the molecular structure is very consistent and lots of detergents in it so it keeps everything clean. Plus you can find it in every Wal-Mart
 
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eighty6gt

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I change mobil 5w20 every 5,000 miles, drive the car pretty hard, have a blower, and oil analysis says I could keep going. 3k seems pretty short.
 

05gtowner

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Are you using syn or conventional. I would go 3K for conventional and up to 5K for syn.
 

eighty6gt

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Synthetic. I bet I could do 8,000 miles. Depends on how long you thing the rest of the car will last. I think engines don't usually go down to wear anymore, they blow up due to the weak rods, phaser failure, oil pump failure, plugging of those vct screens, or the rest of the car falls apart around the engine.
 

nbk13nw

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I change mine monthly regardless of mileage. Peace of mind I guess. Hitting 165k now and still running strong. Have always used full synthetic.

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Grabber

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I will only put synthetic in the car. Amsoil 5W50 and it meets Fords requirements so warranty will not be denied if motor failure occurs.

I have peace of mind knowing the oil is good and I'm not putting crap in my motor.

To each their own.
 

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