What makes Pentosin CHF 11S better?

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I can't find much information about this stuff. All I know is that it costs about $15 a quart, has a wierd fruity-type smell, and that most European vehicles specify it.

What makes it better than ATF or regular GM power steering fluid?
 
Extremely high VI of 320, thin CST, and supposedly very selective synthetic basesocks and additives make it special.
 
It's only matched by aviation grade hydraulic fluid. If you tried to buy that stuff, it would probably cost as much or more
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This is the kinda stuff that makes you want to ring the neck of the guy who must have poured over spec sheets until he found the most obscure fluid he could come up with before designing a system around it.

I guess it could actually make the system simpler ...in that fluid viscosity would remain in a narrower range over broad temp spans ..but I imagine that this can only be a factor until the fluid reaches some operational temp
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. What are the negative side effects of not having that broad VI? What difference does it make if you never go outside a certain temp range? Someone's -25 is another's -5 ..is another's +20 is another's + 45. Every one of those people will experience the same visc at different times of operation ..and vastly different viscs at some point in operation ..regardless of if the fluid had a 320 VI or 599 VI or a 155VI.
 
My Saab specifies it but the manual states that regular GM power steering fluid can be used for top-up. I don't believe the system requires the usage of CHF 11S, but that is what the factory fill is.

Could fluid life have been a reason for using it? Rack and pump life? Prevention of "morning sickness" 15 years down the road?

I am of course making the assumption that the power steering system is not specifically designed for CHF 11S, but the manual's suggestion to use regular GM power steering fluid for top-up backs that assumption up.
 
Its really simple. In certain cold climates, PS systems don't work too well. The high VI allows those northern euro vehicles to have a 'working' PS system in the coldest weather. Others up north will also benefit, eh?
I can noticed the difference between M1 ATF and normal mineral Dexron-III in my PS system and its only 16 degrees F outside now. Thanks to global warming and the big ozone hole, this has so far been a mild winter.

Less pump stress, less rack stress, less HP/MPG wasted,... are some side benefits.

The higher end synthetic can also be labelled 'lifetime' by the marketing departments.

Don't forget that some PS systems run overly hot. The super duper fluid can tolerate that heat without performance degradation and without shortening the life of the entire system.

I don't see the PS system designed around that fluid. I see the fluid as a bandaid for the weaknesses in the system. Weakness are now more evident then ever before in many automotive systems.
 
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I don't see the PS system designed around that fluid. I see the fluid as a bandaid for the weaknesses in the system. Weakness are now more evident then ever before in many automotive systems.




It's not like Pentosin 11s is a new type fluid. It's been around since, uhm, I can't remember, but it's been over 12 years.
 
Its just not for power steering systems,it is used in many Euro cars for hydraulic suspension and brakes,Audi,RR,Jaguars and a few others are using the Citroen system,the PS,brake booster,the main braking system fluid and suspension all use the same pump and fluid.These cars are identified by the green cap on the fluid reservoir.Not all models use this system or even all components of the system but it makes sense to me that they would use the same rack and pump in all vehicles. The Citroen type rack is unique in the sense it is self centering,not all users of the design utilize this feature.Newer versions of this system are speed controlled to divert pressure from the PS to the braking system at higher speeds.This is definitely not a poor design or lower quality unit using the fluid as a band aid.Castrol CHF can be subsituted for the Pentosin.
 
Citroen use Castrol LHM+ in their central hydraulic system.

Castrol CHF is interchangeable with Pentosin CHF 11s and is used in VW, Audi, Seat and Skoda power steering, convertible hydraulic systems, hydraulic transmissions, Daimler Chrysler power steering and ABC suspension, BMW leveling systems and central hydraulic systems, Opel electro-hydraulic power steering, Ford Galaxy power steering, Porsche convertible hydraulic, Porsche Boxter steering, Rolls Royce and Bentley power steering and hydraulic systems of the Silver Seraph and Arnage, and Saab and Volvo power steering.

Yeah, it's super-duper-ultra rare.
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Citroen use Castrol LHM+ in their central hydraulic system.

Castrol CHF is interchangeable with Pentosin CHF 11s and is used in VW, Audi, Seat and Skoda power steering, convertible hydraulic systems, hydraulic transmissions, Daimler Chrysler power steering and ABC suspension, BMW leveling systems and central hydraulic systems, Opel electro-hydraulic power steering, Ford Galaxy power steering, Porsche convertible hydraulic, Porsche Boxter steering, Rolls Royce and Bentley power steering and hydraulic systems of the Silver Seraph and Arnage, and Saab and Volvo power steering.

Yeah, it's super-duper-ultra rare.
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WM? PB? AAp? AZ?
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Are Pentosin CHF 11s and Pentosin CHF 202 interchangable for power steering applications?

Product page link:
http://www.pentosin.de/shop.php?c=214,228




Neither the product description nor the respective PDF data sheets say anything about compatibility or interchangeability between those two products. CHF 11s is a full synthetic fluid, CHF 202 is a semi-synthetic fluid.

Looking at the specs, CHF 202 is thicker when cold and has a higher pour point than the what appears to be superior CHF 11s. Both fluids meet the same quality level (ISO 7308).

The CHF 11s data sheet does not list Audi, which is strange, since my Audi requires that fluid. The CHF 202 data sheet lists VW.

CHF 202 must be a fairly new fluid, and based on the data sheets, I would expect CHF 11s and CHF 202 to be compatible. I would suggest that somebody take a look at a bottle of CHF 202. If it's compatible with CHF 11s it should say it right on it. But what about seal compatibility?
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I've heard that Pentosin may not be compatible with some of the metals in PS systems. Can someone comment on this?
 
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