Is Mobil 1 75-90 a group three oil?
Is mobil syn gear oil a "real" synthetic?
- Thread starter ben walker
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tooslick:
Where are you finding that M1 is MT-1 rated? I can't find that on their website. I was also under the impression that MT-1 gear lubes were safe to use in a GL4 tranny, yet Mobil specifically prohibits this due to the additive package and softer metals. Am I misinformed or just missing something?
"Mobil 1 Synthetic Gear Lubricant is suitable for all automotive applications where lubricants meeting API Service GL-5, are recommended. It can also be used in rear axles where an API Service GL-4 lubricant is recommended. It should not be used in any transmissions requiring an engine oil or automatic transmission fluid, or GL-4 performance level."
Mobil 1® Synthetic Gear Lubricant
[ November 23, 2002, 06:09 PM: Message edited by: BOBISTHEOILGUY ]
Mobil 1® Synthetic Gear Lubricant
[ November 23, 2002, 06:09 PM: Message edited by: BOBISTHEOILGUY ]
Ken,
George Morrison at AVLube - a site sponsor - knows more about Mobils synthetics than anyone I ever met. He said that the M1, 75w-90 is just fine in GL-4 applications. In fact, the VW TDI rally car is using it over in Europe.
The problem with using GL-5's in transmission applications had to do with older chemistries that cause high temp corrosion of "yellow metals", due to the high level of EP additives. All the premimum 75w-90 synthetics are using a much higher quality additive chemistry that does not cause this problem. FWIW, I've run GL4/GL5 synthetics in VW transaxles for over twenty years and have never had any problems.
TS
George Morrison at AVLube - a site sponsor - knows more about Mobils synthetics than anyone I ever met. He said that the M1, 75w-90 is just fine in GL-4 applications. In fact, the VW TDI rally car is using it over in Europe.
The problem with using GL-5's in transmission applications had to do with older chemistries that cause high temp corrosion of "yellow metals", due to the high level of EP additives. All the premimum 75w-90 synthetics are using a much higher quality additive chemistry that does not cause this problem. FWIW, I've run GL4/GL5 synthetics in VW transaxles for over twenty years and have never had any problems.
TS
That's part of what I don't understand. I read that and it seems that Mobil specifically prohibits the use of this gear lube in a tranny that is speced for GL4 only. Yet many people say it's okay and have good luck using it. What really throws me, is that I think Mobil's marketing practices are similar to Amsoil's in some ways, yet they back off on this product. I just wonder why?
The reason (I think) everyone reports having good luck with it is that the effect on the synchros takes a long time. Also Molakule mentioned requires moisture to start off the reaction. I read somewhere GL5 in a tranny supposed to use GL4 will reduce synchro life by half. So you would not notice for a while. Yes there are some GL5 that are ok for GL4 use as well but I don't think M1 is one of them. Why would they be so specific about prohibiting it's use in that application? Surely they would want to sell as much as possible if it really was safe...
Schaeffer's specifically advertises on their #267:
5. Enhanced protection of copper, brass and bronze components from corrosion.
6. Non-corrosivity to brass, bronze and other non ferrous metal parts.
Additionally it is MT-1 and MIL-PRF-2105E
(however MT-1 is actually a spec for NON-syncronized trannies, just that someone brought it up about M1)
Mobil-1 does not do the same and I would not feel safe using it.
Schaeffer's specifically advertises on their #267:
5. Enhanced protection of copper, brass and bronze components from corrosion.
6. Non-corrosivity to brass, bronze and other non ferrous metal parts.
Additionally it is MT-1 and MIL-PRF-2105E
(however MT-1 is actually a spec for NON-syncronized trannies, just that someone brought it up about M1)
Mobil-1 does not do the same and I would not feel safe using it.
I have experience with fleets that are running M1 SHC 75W-90 in their synchro transmissions and have well over 1,000,000 miles and have never lost a synchro, nor a transmission component. *The* reason Mobil will not/does not state GL-4 rating for the formulation is that there is NO GL-4 rating! GL-4 was superseded by GL-5, the test apparatus for certifying to GL-4 no longer exists and therefore the current Mobil 1 75W-90 cannot be tested/approved as a GL-4 lubricant. Mobil is very strict about putting approvals on their products; i.e. the tests must really have been performed and successfully completed. Pretty difficult to approve a formulation for a test/rating when it does not exist..
That said, as TS has indicated, the yellow metal agressiveness does not apply to the current Mobil 1 75W-90 formulation. In fact, many formulations ago Mobil 1 DID carry both the GL-4 and GL-5 approvals; that was when the test/equipment were still in effect..
So, one might ask how people are putting GL-4 approvals on oils when there is no longer a valid test procedure or even a rating?? Interesting......
George Morrison, STLE CLS
That said, as TS has indicated, the yellow metal agressiveness does not apply to the current Mobil 1 75W-90 formulation. In fact, many formulations ago Mobil 1 DID carry both the GL-4 and GL-5 approvals; that was when the test/equipment were still in effect..
So, one might ask how people are putting GL-4 approvals on oils when there is no longer a valid test procedure or even a rating?? Interesting......
George Morrison, STLE CLS
Thanks for the clarification George ...that's about the way I remember it from the last time this issue came up.
Why folks believe websites created by software engineers over folks who actually do this stuff for a living always amuses me ...
TooSlick
Why folks believe websites created by software engineers over folks who actually do this stuff for a living always amuses me ...
TooSlick
Because if it's listed on the website people can take that as a corporation endorsing that particular use. If it's just a person, no matter how knowledgeable, if they are wrong, there is no liability to them. Sometimes reassurance is a good thing. Do you really think airport security is that much better than it used to be?? People THINK it is, so it's alright with them, even though insiders know it's still a joke.
Edit: Nissan still specs 75W-90 GL4 only fluid in there transmissions as well.
[ November 23, 2002, 02:34 PM: Message edited by: mdv ]
Yes - Thank you George. You are about 6 months too late with this information for me. I changed my son's trans oil with the Mobil 1 Gear Lube ($20). After calling the Mobil Tech #- I decided to drain it out at 25 miles and replace it (another $20) with GM Synchromesh Trans Lube. Most expensive flush ever
[ November 23, 2002, 08:55 PM: Message edited by: Al ]
[ November 23, 2002, 08:55 PM: Message edited by: Al ]
I was reading the latest (January!) issue of Sport Compact Car and I found this amusing tidbit in an article about a Nissan 300Z project car:
"To protect our transmission, we went with Red Line 75W140NS gear oil, which is the heaviest bodied, slickest lube Red Line would recommend for a syncro-equipped transmission. The "NS" means that it has friction modifiers for a limited-slip diff. This means maximum lubricity for highly loaded gears. We wanted a heavy lube because our transmission was making screaming noises when the boost was turned up and the engine hit its torque peak. Mike Smith assured us this was normal for a really powerful Z and the transmission would not break."
and
"When draining the Mobil 1 synthetic gear oil, we were dismayed to find it almost black, burnt smelling and thin, with water-like viscosity. Not good. Since the Z has a huge, mega-beefy 230mm riung gear, which is bigger than the venerable Ford 9-inch rear end, we used more conventional Red Line 75W90 Gear oil that's compatible with limited slip differentials. The Red Line gear lubes rendered our once loud drivetrain totally silent and have improved our shifting action."
When you consider that the Red Line gear oil is not much more expensive than other high performance gear oils, why go with anything else?
--- Bror Jace
"To protect our transmission, we went with Red Line 75W140NS gear oil, which is the heaviest bodied, slickest lube Red Line would recommend for a syncro-equipped transmission. The "NS" means that it has friction modifiers for a limited-slip diff. This means maximum lubricity for highly loaded gears. We wanted a heavy lube because our transmission was making screaming noises when the boost was turned up and the engine hit its torque peak. Mike Smith assured us this was normal for a really powerful Z and the transmission would not break."
and
"When draining the Mobil 1 synthetic gear oil, we were dismayed to find it almost black, burnt smelling and thin, with water-like viscosity. Not good. Since the Z has a huge, mega-beefy 230mm riung gear, which is bigger than the venerable Ford 9-inch rear end, we used more conventional Red Line 75W90 Gear oil that's compatible with limited slip differentials. The Red Line gear lubes rendered our once loud drivetrain totally silent and have improved our shifting action."
When you consider that the Red Line gear oil is not much more expensive than other high performance gear oils, why go with anything else?
--- Bror Jace
Bror,
In this case, you are simply switching to a much more viscous oil in the 75w-140. Kind of like putting in 20w-50 instead of 5w-30 in an older motor. Not at all a fair comparison ....
I do think the Redline 70w-80, MTL is kind of a unique product and excellent for transmissions that call for a lighter gear lube. However, there is no magic to the way it works - it is simply much thinner than even a 75w-90 synthetic at all temps:
Viscosity @ -40C/40C/100C
MTL, 70w-80............16,000 Cp/58 Cst/10.1 Cst
Mobil 1, 75w-90 ....135,000 Cp/106 Cst/15.3 Cst
Amsoil 75w-90 ........35,000Cp/113 Cst/15.7 Cst
Now do you understand why MTL transmissions shift so well? Even on a 100+F day, it's only half as thick on a "cold start" as most 75w-90 synthetics.
TooSlick
In this case, you are simply switching to a much more viscous oil in the 75w-140. Kind of like putting in 20w-50 instead of 5w-30 in an older motor. Not at all a fair comparison ....
I do think the Redline 70w-80, MTL is kind of a unique product and excellent for transmissions that call for a lighter gear lube. However, there is no magic to the way it works - it is simply much thinner than even a 75w-90 synthetic at all temps:
Viscosity @ -40C/40C/100C
MTL, 70w-80............16,000 Cp/58 Cst/10.1 Cst
Mobil 1, 75w-90 ....135,000 Cp/106 Cst/15.3 Cst
Amsoil 75w-90 ........35,000Cp/113 Cst/15.7 Cst
Now do you understand why MTL transmissions shift so well? Even on a 100+F day, it's only half as thick on a "cold start" as most 75w-90 synthetics.
TooSlick
TooSlick, you might want to read that piece again. They were changing BOTH the tranny and rear diff oil. In the tranny they put in the thickest stuff available. In the rear end, they used 75W90. Very different oils but both quieted down gear whine/howl, according to the writer's testimony.
Yes, I know that MTL is exceptionally thin ... especially for a gear lube. This is the primary reason for its excellent shift feel ... especially in extreme cold (anything below 0F).
--- Bror Jace
[ November 24, 2002, 06:09 PM: Message edited by: Bror Jace ]
Yes, I know that MTL is exceptionally thin ... especially for a gear lube. This is the primary reason for its excellent shift feel ... especially in extreme cold (anything below 0F).
--- Bror Jace
[ November 24, 2002, 06:09 PM: Message edited by: Bror Jace ]
George, by looking at the MSDS on Mobil's site it appears that the 75w90 M1 is a group three. I am not talking about the SHC gear oil, just the regular silver bottle mobil 1 gear.
This was quoted above:
This is confusing. So someone doesn't get this wrong, The following is quoted from the RedLine web site:
The regular Red Line Gear Oils DO have limited slip additive.
Mobil 1 75W-90 and Mobil SHC 75W-90 are both group IV oils. The only difference between the Mobil 1 and regular truck SHC 75W-90 is that the silver bottle Mobil 1 contains limited slip additization. SHC75W-90 does not contain the limited slip additive and is only available in 5 gallon containers and larger.
Mobil 1 75W-90 is OEM install in all Porsche's which have one incredible set of synchronizers.... And a lot of yellow metal.. And Porsche *requires* its use for warranty..
George Morrison, STLE CLS
Mobil 1 75W-90 is OEM install in all Porsche's which have one incredible set of synchronizers.... And a lot of yellow metal.. And Porsche *requires* its use for warranty..
George Morrison, STLE CLS
Thanks for clearing that up George.
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