Best fluid for BMW 6 speed Manual?

[MolaKule]

Quote:
Redline's ATFs aren't normal ATFs. Redline blends them so that they provide GL-4 protection for MTXs.


Redline blends ATF's with ATF additive packages. There is nothing special about it except the base oils contan more GroupIV's and V's than most American MTL's.

The GL-4 claim is just plain confusing and in my view, marketing hooey.

I would suggest to the OP he first try the Redline MTL70W80 as it contains an MTL specific additive package.

The next lower viscosity MTL would be RP's Synchromax at 7.6 cSt which contains an MTL specific additive package.

The next lower viscosity would be the the Castrol Syntrans at 6.1 cSt or the Honda MTFII which contains an MTL specific additive package.

 

[MolaKule]

or the BMW LT-3 fluid is one of those low viscosity 6.1 cSt MTL's.

Quote:
I read an article by Mike Miller (supposedly a BMW guru of sorts?) stating that ATFs aren't really very good at lubricating bearings. He said that he'd always use MTL unless he couldn't trust the driver to shift proerply in cold weather, in which case he'd use the D4.




I totally agree.

 

[JHZR2]

right... Back to the BMW LT-3 fluid.

A fluid with an ATF-like viscosity, but an MTF designed pack.

Notionally Redline with a GL-4 pack is beneficial over standard ATF, but Ive not seen the VOAs to make this for sure.

Given that the LT-3 is specific to MTs, which I assume it is, and thus it is NOT an ATF, Id use it with confidence. Just not on a lifetime fill scenario...

 

[TheRuss]

And we're saying the BMW LT-3 fluid is Pentosin MT2?

So it's the Pentosin for a freshen up, or Redline MTL for a thicker alternative?

The Royal Purple being slightly thicker sounds like a good middle ground, but then everything I've read tends to suggest that Redline or OEM is better than RP.

 

[TheRuss]

Also, I don't really understand the ratings of the fluids. The Pentosin is a 75W80 and the Redline MTL is a 70W80, which would suggest to me that the MTL is thinner at lower temps, however, that's not the case - the Pentosin is actually thinner at all temps.

Confusing!

 

[badtlc]

Originally Posted By: TheRuss

The Royal Purple being slightly thicker sounds like a good middle ground, but then everything I've read tends to suggest that Redline or OEM is better than RP.


My only concern with RP Synchromax is they don't list an acceptable GL use anywhere, but lots of people use it and are happy with it.

 

[d00df00d]

When you say "thinner at all temps," are you referring to the kinematic viscosity numbers at 40º C and 100º C?

The W numbers are based on measurements at temps much lower than 40º C and involving higher levels of mechanical shear.

 

[badtlc]

Originally Posted By: d00df00d
When you say "thinner at all temps," are you referring to the kinematic viscosity numbers at 40º C and 100º C?

The W numbers are based on measurements at temps much lower than 40º C and involving higher levels of mechanical shear.


He is talking viscosity measured at all temps (-20C, 0, 40C, 100C, etc.)

 

[badtlc]

Originally Posted By: JHZR2
right... Back to the BMW LT-3 fluid.

A fluid with an ATF-like viscosity, but an MTF designed pack.

Notionally Redline with a GL-4 pack is beneficial over standard ATF, but Ive not seen the VOAs to make this for sure.

Given that the LT-3 is specific to MTs, which I assume it is, and thus it is NOT an ATF, Id use it with confidence. Just not on a lifetime fill scenario...


I have some extra Redline MTL sitting around. WOuld a VOA be beneficial? And if so, what measurements would be needed because my lab doesn't do all the same measurements as someone like blackstone.

 

[MolaKule]

Here are the major additive values for Redine ML70W80 to the nearest significant figure:

Calcium - 3500
Phos - 2400
Zinc - 2600

Viscosity, 10.1/52

The AW addpack is pretty substantial for a GL-4.

 

[MolaKule]

Quote:
Also, I don't really understand the ratings of the fluids. The Pentosin is a 75W80 and the Redline MTL is a 70W80, which would suggest to me that the MTL is thinner at lower temps, however, that's not the case - the Pentosin is actually thinner at all temps.



Disregard. They are simply splitting hairs.

 

[MolaKule]

The four MTL fluids closest to a Kinematic Viscosity of 6.1 (About the same viscosity as a DexronVI) or so are the:

Castrol Syntrans FE 75W,

the BMW LT-3,

Honda MTII.

Another fluid in this category is the Ford FML-XT-11-QDC
Dual Dry Clutch.

These are low 6.X viscosity MTL's with a Manual Transmission specific additive package with a GL-4 protection rating.

 

[badtlc]

And Fuchs FE 75w & Pentosin mtf2

 

[TheRuss]

So will Redline MTL "protect" my trans any more than the Pentosin? With regards to the extra power going through it etc? If there's no benefit to the thicker MTL, then Pentosin would sound like the best bet.

 

[MolaKule]

I dunno, do you have a Pentosin VOA?


https://bobistheoilguy.com/forums/threads/manual-transmission-fluids-and-their-viscosities.198101/

 

[TheRuss]

Nope, only this for technical info: http://www.pentosin.net/specsheets/Pentosin_MTF-2.pdf

Thing is, I know my transmission is supposed to have a thin oil in it, but all the manufacturers are moving to thinner oils, seemingly to improve fuel economy and lower emissions. Question is - is moving to these thinner oils actually good for my car? If not, I'd rather stick something thicker in IF (and it's a big if) the thicker oil will protect my transmission better.

Will Redline MTL protect my trans better than the Pentosin?

Will the Pentosin make mpg etc noticeably better?

Which will have the best cold shifting properties?

I'm not sure that anybody can answer all of the above for me.

 

[MolaKule]

Originally Posted By: TheRuss
Nope, only this for technical info: http://www.pentosin.net/specsheets/Pentosin_MTF-2.pdf

Thing is, I know my transmission is supposed to have a thin oil in it, but all the manufacturers are moving to thinner oils, seemingly to improve fuel economy and lower emissions. Question is - is moving to these thinner oils actually good for my car? If not, I'd rather stick something thicker in IF (and it's a big if) the thicker oil will protect my transmission better.

Will Redline MTL protect my trans better than the Pentosin?

Will the Pentosin make mpg etc noticeably better?

Which will have the best cold shifting properties?

I'm not sure that anybody can answer all of the above for me.


Without knowing the EXACT viscosity of the fluid BMW specifies I have the following comments and Please read this series of White Papers:

https://bobistheoilguy.com/forums/threads/synchromesh-manual-transmission-lubricants.93561/

If your vehicle is suspected of using or requiring an ATF-like viscosity fluid then I think any of these fluids listed below will work well and get you good fuel mileage and ample wear protection -

Quote:
A. The four MTL fluids closest to a Kinematic Viscosity of 6.1 (About the same viscosity as a DexronVI) or so are:

1. Castrol Syntrans FE 75W,

2. BMW (Pentosin) MTF-LT-3,

3. Honda MTII or MTF 2.

4. Ford FML-XT-11-QDC


B. The next higher viscosity MTL would be the 7.5 cSt versions (About the same viscosity as a DexronIII)

1. Royal Purple's Synchromax

2. Ravenol MTF-2

3. Honda MTF

4. VW part number G052512A2

5. GM Manual Transmission and Transfer Case Fluid

6. BMW (Pentosin) MTF-LT-1, 2


C. The next higher viscosity MTL would be Castrol Syntrans V FE 75W-80 8.0cSt

D. The next higher viscosity MTL would be BG Synchroshift II 8.2 cSt

 

[TheRuss]

Could putting in something thicker than those fluids be detrimental to my gearbox if it's designed for an ATF-like thin fluid? As I understand it, the Redline MTL, although in the 10.X cst range, is actually still quite a thin, almost watery fluid.

Also, the word "ample" with regards to wear protection doesn't feel right for me. I want good, or excellent protection, not ample...!

 

[MolaKule]

Originally Posted By: TheRuss
Could putting in something thicker than those fluids be detrimental to my gearbox if it's designed for an ATF-like thin fluid? As I understand it, the Redline MTL, although in the 10.X cst range, is actually still quite a thin, almost watery fluid.

Also, the word "ample" with regards to wear protection doesn't feel right for me. I want good, or excellent protection, not ample...!


You're putting us on, right?

You have been given the recommendations and data so you have to decide.

The MTL70W80 is not "watery," it is a 10.0 cSt lubricant.

Experiment with the various fluids and see.

These are as good as current technology gets. There is such thing as zero risk. Each tranny his a slightly different feel with varying synchro, shifter assembly, and bearing wear.

Quote:
A. The four MTL fluids closest to a Kinematic Viscosity of 6.1 (About the same viscosity as a DexronVI) or so are:

1. Castrol Syntrans FE 75W,

2. BMW (Pentosin) MTF-LT-3,

3. Honda MTII or MTF 2.

4. Ford FML-XT-11-QDC


B. The next higher viscosity MTL would be the 7.5 cSt versions (About the same viscosity as a DexronIII)

1. Royal Purple's Synchromax

2. Ravenol MTF-2

3. Honda MTF

4. VW part number G052512A2

5. GM Manual Transmission and Transfer Case Fluid

6. BMW (Pentosin) MTF-LT-1, 2


C. The next higher viscosity MTL would be Castrol Syntrans V FE 75W-80 8.0cSt

D. The next higher viscosity MTL would be BG Synchroshift II 8.2 cSt

 

[TheRuss]

OK folks, so I ended up buying the Pentosin MTF-2, put it in yesterday and now somebody on another forum suddenly tells me it's the wrong fluid. Is this right?

My transmission had a sticker on saying BMW-LT-3 fluid. I didn't think the "MTF-2" name of Pentosin's product had anything to do with the BMW LT-X ratings, but looking at the below PDF, the top BMW part number appears to relate to a BMW MTF-LT-2 fluid, which supposedly my car isn't supposed to use, but instead it should use MTF-LT-3.

http://www.pentosin.net/specsheets/Pentosin_MTF-2.pdf

On page 8 of this PDF (below) you can see that same part number from the above MTF-2 pdf, listed next to BMW's MTF-LT-2 fluid...

Will I be OK with the Pentosin MTF-2 in my transmission, or should I get it out ASAP? I can't see an other MTF fluids that Pentosin make... what could be in the MTF-2 that would mean my transmission can't use it?

Just for reference, the transmission feels OK at the moment, but if it's not optimal or might do damage I'd rather get the Pentosin out ASAP.

Help!