I have searched and am more confused by tons of input on the subject mostly from internet mechanics, no offense intended.

I would like to do the trans service on a 2009 Cayenne S. The Porsche ATF is a joke cost wise.

I would appreciate a recommendation from a real expert as to a alternative to the Porsche ATF

 

If you elect to not use the Porsche ATF fluid then you can chose any fluid using any criteria you want. Cost. Color of the bottle. Taste. Whatever.

Porsche states a specific fluid service interval because it has run enough test mules enough miles to believe the fluid will be just fine.

If you do not use this fluid then you are throwing away all the testing Porsche has done. Do you really think anyone owner, any number of owners, who have used some other fluid really match up test wise to the testing Porsche has done?

Also, there is the concern of miscibility. You have to worry the replacement fluid is not compatible with the Porsche fluid.

So, you really should drain the transmission, including its converter, then refill with your brand of ATF then run the transmission a while the redrain and refill with fresh fluid again to flush the old Porsche fluid out so only the new fluid is present.

All this fluid and labor is going to make the cost of the Porsche fluid more competitive.

Of course if you believe any ATF is like any other then you probably don't put much weight on miscibility and you can then just do whatever you need to get by.

Nice of you to use your car's $10K (or more) transmission as a fluid test bed to see if you can save a few bucks on fluid.

 

Mobil 3309
955, 957, Touareg, Audi Q7 -> they all share the same transmission and it's filled with this. Transmission is made by Aisin and you can also use a variety of Toyota, VW ... fluids and it's still gonna be the same as Mobil 3309 spec wise.

 

Thanks. That is the info needed.

 

TurboTodd,

Servicing the transmission is far more complicated than simply changing the fluid. Not only is the proper fluid required but also the following items- plus the proper procedure. As above, do you want to experiment with an expensive transmission? This is provided by the PCA.

Required tools and parts:

-The Porsche PIWIS (Porsche Integrated Workshop Information System) diagnostic tool for proper filling of transmission fluid and performing transmission adaptation procedure

-12 – 14 liter capacity fluid container

-Assorted metric sockets, wrenches and screwdrivers

-1/4” drive IN/lb. torque wrench

-3/8” drive FT/lb. torque wrench

-Cleaning materials (solvent) and towels (Lint free towels are imperative for this procedure)

-Transmission filter screen (Genuine Porsche Preferred)

-Transmission filter screen O-ring (Genuine Porsche preferred)

-Transmission oil pan gasket (Genuine Porsche preferred)

-10 Liters of genuine Porsche transmission fluid (oil)

-Oil pump with reservoir and hose (for filling the transmission with fluid-oil)....

 

I use fluid from the Porsche Approval List, but I'm not a real expert.

 

Yep.

There are areas where it's Porsche only parts, and there are areas where you don't need to pay the Porsche price tag. There are Porsches that have actual high-tech trannies need specific fluid, and I'd run nothing but what Porsche specs. But, this isn't a high-tech tranny.

 

I have used Redline ATF in all my German cars for about 15 years including my cayenne! Very good stuff!

 

I am on the cusp of changing mine with the Toyota ATF brand, as described in one of the threads (I think its a sticky now).
yes, it is a Porsche. yes, they would love for you to believe that they have a secret fluid for everything. Yes, others did analysis on the fluids and compared to others and that is why I am deciding to go with that.

 

+1^

I have had a lot of good luck with Redline oils, the oly thing I have not used in their lineup is the motor oil. From 2 stroke r/c airplanes to Superbikes, musclecars, imports and everything in between. In fact I had a Turbo AWD Eclipse GSX with a short ratio diff and tranny, would barely shift without the mtl. Killer stuff!!

 

3rd. Redline in all of the CTT drivetrain components, plus redline 5W-40 in the summer, and 0W40 in the winter. It's one of the few good oil companies that makes both 0W40 and 5W40 fluids. I don't like switching between companies to get a winter weight, and M1 is far too thin for a summer weight.

 

mobil 3309 is only correct oil. of course smbd can use even cooking oil since it will be in his own car for his money.

 

Thanks for all the input.

I too have used redline drive line products in other cars. From the weeks of research I have done I believe the redline is actually an upgrade to the OEM trans fluid.

Going with redline for the trans, transfer case and diffs.

For engine oil I am going with Joe Gibbs Driven DT-40. No debate there.

ECS put together a nice kit for me. I think I will give a go this weekend.

 

Nice! Make sure you get the filter and gasket for the trans fluid. It's easy to do. I'd also try and get enough trans fluid for two fluid changes as that's about what it takes to completely change the fluid. Then, going forward you can just do a single fluid change knowing that, while there will be some older fluid left behind, it's still all Redline fluid in there.

 

I'm not about to change my own anymore although I might top it off if needed. Does anyone know how many qts are usually drained compared to the published capacity?

Some automatic trannies only give up about half their fluid when drained for a 'change'.