Renewable Lube ATF compatible for PS fluid?

[dparm]

BMW calls my car's power steering fluid "lifetime" but I of course don't trust that. The car just ticked 50k and its 3rd birthday is tomorrow.

The factory fill is Pentosin CHF11S. I have no worries about using this stuff, but I see that ATF is considered an acceptable substitute for about half the price. Red Line recommends the D4 ATF, but I am already planning to order Renewable Lube's 75w140 gear oil and thought I could maybe just throw in a bottle or two of their "BioSyn-Xtra ATF PLUS" and save on shipping. It's hard to get anything less than a case of Red Line.

http://www.renewablelube.com/TDS/4D-%20B...ion%20Fluid.pdf

Is that fluid going to be okay for my power steering system? Is there any reason NOT to use ATF versus the Pentosin? Both seem to sport the same suitability lists: Dexron III, Dexron IIIH, Mercon V, etc.

 

[JHZR2]

Not sure why you'd want to save $5 on a $50k car.

Someone had to say it, figured Id get it taken care of...

With that aside, doesnt the Pentosin fluid have a crazy-high VI? I would imagine the ATF doesnt? Not sure if PS systems have crazy-high shear characteristics, and worse than ATs... Or more of a heat issue...

For something that generally doesnt see a consistent change interval, Id be a little worried about the long-term polymerization potential of RLI. Maybe that's not the case.

Personally, Id go with Amsoil SVG, and stick with the pentosin. Ive not been that impressed with redline in my E30 diff, and Ill not put it in the E88 (though I do intend to replace the diff fluid and the MTF at some point in that car). Im planning to go SVG either 75w-110 or w-140, and then probably BMW OE MT-3 unless I can find a truly OE equivalent fluid...

 

[MolaKule]

I would suggest you confer with Mr. Bill Garnier at (330) 877-9982.

 

[dparm]

Originally Posted By: JHZR2
Not sure why you'd want to save $5 on a $50k car.

Someone had to say it, figured Id get it taken care of...

With that aside, doesnt the Pentosin fluid have a crazy-high VI? I would imagine the ATF doesnt? Not sure if PS systems have crazy-high shear characteristics, and worse than ATs... Or more of a heat issue...

For something that generally doesnt see a consistent change interval, Id be a little worried about the long-term polymerization potential of RLI. Maybe that's not the case.

Personally, Id go with Amsoil SVG, and stick with the pentosin. Ive not been that impressed with redline in my E30 diff, and Ill not put it in the E88 (though I do intend to replace the diff fluid and the MTF at some point in that car). Im planning to go SVG either 75w-110 or w-140, and then probably BMW OE MT-3 unless I can find a truly OE equivalent fluid...



Valid point, but it's a difference of about $15/L. I have no problem spending extra on Pentosin. And yes, it has a VI of 313. The ATFs seem to have VIs around 180.



As for the rear diff, the factory stuff is Castrol SAF-XJ +FM and it's about $45/L. Not many sources for that in the US, though I've heard Mercedes uses it in the AMG cars and sells it for half as much (sans FM).

RLI's fluid is pretty impressive when you look at the specs. Red Line's isn't far off, nor is Motul's. They all carry higher VIs and pour points than the SAF-XJ and cost about 1/3 as much.

 

[JHZR2]

I was just giving a hard time about the $5. I figured someone else would say it.

Didnt realize that Fm was necessary. The LSD in my E30 specs XJ but not FM, and has never needed it to operate properly. Im sure yours is set up far differently than that LSD though.

Curious why Amsoil SVG isnt even in the running on your list? Id consider RLI if you have good success. I wish I could still get the Specialty formulations stuff, has been the best diff oil Ive ever used in my 318i LSD.

I too have heard of the individual quarts and superior pricing on XJ from MB.

 

[dparm]

The M cars have LSDs with variable locking. Originally they just used straight XJ and added the FM if the owner complained about chatter, but at some point they just made the factory-fill include the FM.

The SVG is some 10% thicker than the other 75w140s I mentioned, including XJ:

SVG
KV@40: 193.2
KV@100: 27.5
VI: 180


RLI
KV@40: 153.9
KV@100: 25.1
VI: 198


Motul
KV@40: 170
KV@100: 24.7
VI: 178


Red Line
KV@40: 180
KV@100: 27.4
VI: 191


SAF-XJ
KV@40: 177
KV@100: 25
VI: 174

 

[JHZR2]

Interesting, thanks!

So regarding PSF, where is there such a high temperature and high shear point that the VII of pentosin is important?

My understanding is that it is intended for central hydraulic systems, so to be used also in suspensions and other parts, perhaps they are more demanding?

The question is if there is a benefit to the higher VII for PS applications for some reason...

 

[Wilhelm_D]

Originally Posted By: dparm
BMW calls my car's power steering fluid "lifetime" but I of course don't trust that. The car just ticked 50k and its 3rd birthday is tomorrow.

The factory fill is Pentosin CHF11S. I have no worries about using this stuff, but I see that ATF is considered an acceptable substitute for about half the price. Red Line recommends the D4 ATF, but I am already planning to order Renewable Lube's 75w140 gear oil and thought I could maybe just throw in a bottle or two of their "BioSyn-Xtra ATF PLUS" and save on shipping. It's hard to get anything less than a case of Red Line.



The Pentosin is a European style fluid which is much thinner with a much higher VI than ATF:

Pentosin CHF 11s Spec Sheet

with exceptional low temperature characteristics.

Red Line D4 ATF and Renewable Lube 75w140 look to be downgrades.



.

 

[dparm]

Originally Posted By: Wilhelm_D

Red Line D4 ATF and Renewable Lube 75w140 look to be downgrades.




We are confusing two different points here. I am not talking about using 75w140 in the power steering system. RLI's gear oil is far superior on-paper to the factory-fill Castrol SAF-XJ.

 

[901Memphis]

Stick with the oem for sure. Once every 50k sounds about right.

 

[BTLew81]

I believe I have some unopened 11s in the garage I am not going to use I'm in te SW burbs. It's yours if you want it.

 

[dparm]

Originally Posted By: BTLew81
I believe I have some unopened 11s in the garage I am not going to use I'm in te SW burbs. It's yours if you want it.



Sure, how much? Amazon & Pep Boys sell it for $25/L. My folks live in Naperville so I'm in that area sometimes.

If you need any oil, I have two 1qt bottles I don't need (only opened them to do VOAs): Castrol Edge 0w40 & Eneos Sustina 0w50.