Mobil Delvac1 50w Trans Fluid Audi TT Quattro

[tompumped]

I've read a lot about the factory fill fluid which is G052171a2. Some people seem to think it's too thin even for stock power levels and some have seen pitting on races when tearing down their transmissions. Either way it is like water when drained hot. I have no idea how it is rated at a 75w. I'd also love to know why they chose to use a sulfur based oil when the shift forks are brass. I see nobody bring this up. I hope the synchros aren't.

My car has 285hp/290tq and I got three gallons of this mobil delvac synthetic 50w from work for free. It has a gl-4 rating as required, but I read the mt-1 rating is not for transmissions with synchros. I just want to make certain it's not going to hurt the transmission in the long run. The car wont be driven in the winter. I want something that will be better suited for the slightly higher power levels. I don't know much about the cSt rating but redline mt90 seemed notchy at fifty degrees. I haven't tried the mobil yet at fifty degrees but it's in the transmission now. I know that redline makes other thinner fluids which i'll probably end up using or combining with the mt90 I have, but this mobil fluid seems like high quality fluid.

Apparently there are two different mobil 50 trans fluids. The one I have says gl-4 right on the 5 gallon pail.

https://www.mobil.com/English-US/Co...GLXXMobil-Delvac-1-Transmission-Fluid-50

 

[tompumped]

I just test drove the car and it shifts just as good as with the Febi 75w factory specific oil. I just realized it says right on the page it extends the life of synchronizers which contradicts what i've read about the mt-1 spec. I don't understand why this has a higher cSt and it shifts better than the mt90 did at temperature. Why is the cSt so important when selecting a proper trans fluid for the 02M?

I wonder why this has been overlooked when discussing trans fluids. I never knew about it, but they were going to throw out all this oil that was in the back of the shop and I ended up with 3 gallons of this left over in a 5 gallon pail. 10 gallons of unopened mobil MX 15w40 and 10 gallons of kendall 15w40. It was all probably over twenty years old.

https://www.mobil.com/English-US/Co...GLXXMobil-Delvac-1-Transmission-Fluid-50

"It has the same viscosity as most SAE 50 engine oils and SAE 90 gear lubricants at the high end of the temperature-viscosity scale, and because of its inherently high viscosity index, it provides stronger film strength at higher temperatures than conventional oils"

 

[Garak]

Mola has a useful list here. He would likely be able to answer your question, if he stumbles across this thread.

 

[MolaKule]

Originally Posted by tompumped
I've read a lot about the factory fill fluid which is G052171a2. Some people seem to think it's too thin even for stock power levels and some have seen pitting on races when tearing down their transmissions. Either way it is like water when drained hot. I have no idea how it is rated at a 75w. I'd also love to know why they chose to use a sulfur based oil when the shift forks are brass. I see nobody bring this up. I hope the synchros aren't.

It has a gl-4 rating as required, but I read the mt-1 rating is not for transmissions with synchros.

https://www.mobil.com/English-US/Co...GLXXMobil-Delvac-1-Transmission-Fluid-50



The G052171A2 has a rating of 75What, 75W90?

Here some facts:

Extremely hot oil has a lower viscosity than at room temperature. No oil is ever as thin as water.

Many GL-5 Differential lubes have a MT-1 rating because some Off-Road and HD trucks specify it, but most have all steel internals.

IMHO, Anyone who runs a daily driver MTF fluid for racing isn't thinking clearly.

 

[MolaKule]

Originally Posted by tompumped
I just test drove the car and it shifts just as good as with the Febi 75w factory specific oil. I just realized it says right on the page it extends the life of synchronizers which contradicts what i've read about the mt-1 spec. I don't understand why this has a higher cSt and it shifts better than the mt90 did at temperature. Why is the cSt so important when selecting a proper trans fluid for the 02M?


What contradiction are you referring to? Please read the explanation above in your previous post and maybe you can clarify your question.

Viscosity is important and is related to film strength and we would like to keep a film of oil between the gear teeth to protect the tooth faces. When the film breaks, the additive keep the metals from scoring and galling.

Originally Posted by tompumped
I wonder why this has been overlooked when discussing trans fluids...


What has been overlooked and who said what? Can you point to specific quotes or data?


Originally Posted by tompumped
"It has the same viscosity as most SAE 50 engine oils and SAE 90 gear lubricants at the high end of the temperature-viscosity scale, and because of its inherently high viscosity index, it provides stronger film strength at higher temperatures than conventional oils"


Yes sir, please see this:

https://www.bobistheoilguy.com/viscosity-charts/

 

[Y_K]

Audi Quattro TT is clearly stated in the subject title

 

[MolaKule]

Originally Posted by Y_K
Audi Quattro TT is clearly stated in the subject title



Thanks, I guess I missed that somewhere along the way and it has been corrected.

 

[tompumped]

Originally Posted by Garak
Mola has a useful list here. He would likely be able to answer your question, if he stumbles across this thread.

thanks for the link



Originally Posted by MolaKule
Originally Posted by tompumped
I've read a lot about the factory fill fluid which is G052171a2. Some people seem to think it's too thin even for stock power levels and some have seen pitting on races when tearing down their transmissions. Either way it is like water when drained hot. I have no idea how it is rated at a 75w. I'd also love to know why they chose to use a sulfur based oil when the shift forks are brass. I see nobody bring this up. I hope the synchros aren't.

It has a gl-4 rating as required, but I read the mt-1 rating is not for transmissions with synchros.

https://www.mobil.com/English-US/Co...GLXXMobil-Delvac-1-Transmission-Fluid-50



The G052171A2 has a rating of 75What, 75W90?

Here some facts:

Extremely hot oil has a lower viscosity than at room temperature. No oil is ever as thin as water.

Many GL-5 Differential lubes have a MT-1 rating because some Off-Road and HD trucks specify it, but most have all steel internals.

IMHO, Anyone who runs a daily driver MTF fluid for racing isn't thinking clearly.






The Febi oil which i'm almost certain is the same as what's in the VW bottle says 75w on it and that's it. I read a thread on here that had a UOA of this oil and it is thin oil. I had a feeling before I read that thread it was too thin and more than likely engineered for fuel mileage. I'm not racing the car, it's just a daily driver that wont see snow.




Originally Posted by MolaKule
Originally Posted by tompumped
I just test drove the car and it shifts just as good as with the Febi 75w factory specific oil. I just realized it says right on the page it extends the life of synchronizers which contradicts what i've read about the mt-1 spec. I don't understand why this has a higher cSt and it shifts better than the mt90 did at temperature. Why is the cSt so important when selecting a proper trans fluid for the 02M?


What contradiction are you referring to? Please read the explanation above in your previous post and maybe you can clarify your question.

Viscosity is important and is related to film strength and we would like to keep a film of oil between the gear teeth to protect the tooth faces. When the film breaks, the additive keep the metals from scoring and galling.

Originally Posted by tompumped
I wonder why this has been overlooked when discussing trans fluids...


What has been overlooked and who said what? Can you point to specific quotes or data?


Originally Posted by tompumped
"It has the same viscosity as most SAE 50 engine oils and SAE 90 gear lubricants at the high end of the temperature-viscosity scale, and because of its inherently high viscosity index, it provides stronger film strength at higher temperatures than conventional oils"


Yes sir, please see this:

https://www.bobistheoilguy.com/viscosity-charts/


I'd read on here that someone mentioned the mt-1 spec was not for synchros. I was surprised no one discussed this mobil 50w fluid as a viable option for their O2M six speed transmission. After driving to work today it shifts as good if not better than the OEM specified fluid and i'd like to find out if it does offer better protection. As I said before I think it's a mistake to run the factory fluid due to the sulfur-phosphorous? additive as there is brass shift forks but that could be an old wives tale I read on the internet.

Thanks for the info i'll have to read more when I have time. I've never properly researched fluids. I didn't even know why the additives are important.

 

[MolaKule]

Originally Posted by tompumped



...I'd read on here that someone mentioned the mt-1 spec was not for synchros. I was surprised no one discussed this mobil 50w fluid as a viable option for their O2M six speed transmission. After driving to work today it shifts as good if not better than the OEM specified fluid and i'd like to find out if it does offer better protection. As I said before I think it's a mistake to run the factory fluid due to the sulfur-phosphorous? additive as there is brass shift forks but that could be an old wives tale I read on the internet.

Thanks for the info i'll have to read more when I have time. I've never properly researched fluids. I didn't even know why the additives are important.


Have both the factory fill analyzed and have the Mobil 50W fluid analyzed and let's compare both with respect to elemental components and viscosity@100C.

We don't go out and analyze or test drive every potential fluid in the market place for every vehicle but do have some interesting discussions on fluids that have been analyzed.

 

[tompumped]

Originally Posted by MolaKule
Originally Posted by tompumped



...I'd read on here that someone mentioned the mt-1 spec was not for synchros. I was surprised no one discussed this mobil 50w fluid as a viable option for their O2M six speed transmission. After driving to work today it shifts as good if not better than the OEM specified fluid and i'd like to find out if it does offer better protection. As I said before I think it's a mistake to run the factory fluid due to the sulfur-phosphorous? additive as there is brass shift forks but that could be an old wives tale I read on the internet.

Thanks for the info i'll have to read more when I have time. I've never properly researched fluids. I didn't even know why the additives are important.


Have both the factory fill analyzed and have the Mobil 50W fluid analyzed and let's compare both with respect to elemental components and viscosity@100C.

We don't go out and analyze or test drive every potential fluid in the market place for every vehicle but do have some interesting discussions on fluids that have been analyzed.



What company would you recommend? I've never sent out any oil for a UOA/VOA.

It seems that some companies only send you the data and others will give you their opinion and or prior experience doing UOA's on specific oils. There was a good one on this site that was a UOA of the factory fill and the tech said it was pretty standard to see that viscosity and data for that mileage.