Which gear oil? 07 Mustang GT

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3,034
Location
Richmond, VA
My Mustang is my baby, with 30K on her now I figured its time to change out the fluid in the rear end. It does require a friction modifier. If price were a minor consideration which 75w-140 would you use? Also I looked at Mobil 1's website, anyone ever seen their 75-140 in a retail store? I do not recall ever seeing it.
 
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4,370
Location
MS
RedLine, Amsoil Severe Gear, Mobil 1, Motorcraft, Royal Purple. Take your pic, all are good. I personally am most partial to RedLine though, and surprisingly enough you can get RedLine, Amsoil SG and M1 for less $$ than Motorcraft...and you do not have to add friction modifier with those fluids (already have them).
 
Messages
368
Location
Texas
 Originally Posted By: Jason2007
I have Royal Purple in my 07 GT and love it. Its been in there a year and I didnt need to add any extra LS additive. Great fluid.
Same here. My 08 GT had the infamous 8.8 axle minor gear whine since new. I put the Royal Purple Max Gear 75W140 in at about 6k miles and the whine all but went away. I'm at 24k now and all is well. I guess it's pretty good stuff. I too did not have to add any friction modifier.
 
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4,370
Location
MS
 Originally Posted By: oilboy123
1 Amsoil 2 Redline 3 Mobil 1
I'd say: 1. RedLine 2. Amsoil SG 3. Mobil 1 4. RP
 
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651
Location
Iowa
For what it's worth, I have had good results with Motorcraft 75W140 in my 98 F150. And is comes with the friction modifier. (I think???) Personally, I don't think you can go wrong with any of the choices.
 
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14,730
Location
Santa Barbara, CA
 Originally Posted By: Junior
For what it's worth, I have had good results with Motorcraft 75W140 in my 98 F150. And is comes with the friction modifier. (I think???) Personally, I don't think you can go wrong with any of the choices.
the motorcraft gear oil do not come with modifier, you need to add the XL-3 modifier.
 
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962
Location
San Antonio, Texas
You can run the 75-90 in them. I ran 75-90 in my '02 GT for a good while. Even with some friction modifier I still had some chatter in the Tlok and the rear was a little noisy. I recent;y switched to the 75-140, didn't add any friction modifier, and the chatter is pretty much gone. The rear also runs much quieter now. Either will work fine but the 75-140 seems to be the better choice from what I've experienced. Oh yea, both the 75-90 and the 75-140 I've put in have been Mobil1.
 
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