Viscosity Index of 37 - PS fluid

[GMorg]

I bought some PS fluid at O'Reiley's. It was a multivehicle spec that included Honda and domestics (Master Pro Chemicals). I found the pds and was amazed. The VI is listed as 37.

cSt@100 C range 4.75-6.0
cSt@40 C range 29.0-43.5

It was 4.99/quart. I guess you get what you pay for...

I have been unhappy since Valvoline SynPower PS fluid went out of production. I have tried Pentosin, Redline, GM Cold Climate, and now Master Pro Chemicals.

Vehicle, Montana SV6. Symptom, "notchy" in long curves or at low RPM.


Link to pds (you may have to paste it into your browser):

http://www.google.com/url?sa=t&rct=j&q=pds%20master%20pro%20power%20steering%20fluid%20viscosity&source=web&cd=1&sqi=2&ved=0CBoQFjAA&url=http%3A%2F%2Fwww.oreillylubetech.com%2FPDS%2FPSF.pdf&ei=DG3ATtL_BauksQKR0rmhBA&usg=AFQjCNGGClmQvnB-7JhfSnulH1wpJKiasQ&cad=rja

 

[Billbert]

Have you tried LubeGards P/S additive? It seems almost miraculous at solving some P/S problems.

 

[Colt45ws]

I think they meant 73.
If it was 37, 40C range would be 39-61cst.
Still not great. In this case you really DONT get what you pay for since Supertech at walmart is probably nearly identical.

Have you tried an ATF?

 

[Jim Allen]

GMorg- Believe it or not, I'm going to ask you to look at a Lucas Oil product. I just happened onto the site looking at some PS alternatives and have to admit this stuff looks pretty good. 163 VI!

Lucas PS Oil

 

[dailydriver]

The Royal Purple Max EZ p.s. fluid is not too shabby either at a 175 VI.

I have used this in the past and it is one of the few RP products I have been more than satisfied with.

 

[GMorg]

Yesterday I purchased two bottles of the RoyalPurple EZ fluid. I will give the RP a try before I purchase anything else.

By the way, the Lucas PS fluid looks a lot like 5W30 motor oil from a viscosity perspective. It is the highest viscosity PS fluid that I have seen (at operating temps).

I have used ATF in many steering systems. I am tempted to give Mobil 1 ATF a try for my current problem. However, I keep reading that ATFs have some seal issues with GM power steering systems. I use ATF routinely in my wife's Sable.

 

[Jim Allen]

Yeah, that's why I thought it was so interesting. I have RP EZ in both my trucks now and have no complaints.

 

[MolaKule]

That VI has to be in error.

I would think it is 137 instead.

 

[GMorg]

If we calculate the VI using the low ends or the high ends of the ranges, the VI would be 78-80. If we use the low end of the high temp and the high end of the low temp, the VI is 25.8. If use the best combination, the VI is 158. My best guess is that there is a typographical error and the VI is supposed to be listed as 73 like Colt45ws suggested.

 

[GMorg]

I resurrected this thread to give an update.

The Royal Purple EZ was satisfactory, but I thought that I would try Jim Allen's suggestion of Lucas PS fluid. The Lucas fluid gave me the same "notchy" feel that other fluids had produced. So, I have been switching back to Royal Purple EZ. My favorite fluid is still the discontinued Valvoline Synthetic PS fluid, but since it is not available any more, my new favorite is RP.

I think that I have done enough fluid exchanges to have the system completely switched to RP. I have bashed RP SynchroMax as a replacement for VersaTrak (a position that I will defend for my Montana SV6), but I have to give their PSF two thumbs up.

 

[dailydriver]

The Valvoline Max Life p.s. fluid also seems pretty thick at operating temps as well.

 

[GMorg]

The discontinued SynPower PSF had a VI of 334 but wasn't at thick as RP at operating temperature.

Old Valvoline Synthetic PSF data:

Viscosity, mm2/s @ 100 ºC 6.3
Viscosity, mm2/s @ 40 ºC 18.9
Viscosity Index 334
Viscosity, mPa.s -40 ºC. 1100
Evaporation loss % at 150°C. 5.3
Pour Point, ºC (ISO 3016) -54
Specific Gravity @ 15/15ºC 0.813
Flash Point, COC, ºC 150
Colour green

 

[HTSS_TR]

The current PSF in my E430 is Maxlife at about 5-6 years old and 50-60k miles, I'm thinking to change it soon. I had been searching for replacement, either stay with Maxlife or try a new fluid. So far I think I may try Redline or Lubegard PSF, O'Reilly has Redline at $13/qt but no price on Lubegard. The recommended PSF is Fuchs Titan PSF on the MB list 236.3.

Valvoline SynPower PSF seems to be an excellent fluid with extra high VI. The climate in So Cal is mild all year, but extra high VI doesn't hurt.

 

[GMorg]

I agree that the Valvoline product WAS a great product. However, it has not been made in 4 or 5 years.

I think that FEBI also has 236.3 fluid. Or, Mobil ATF-D.