Just wondering what people are using for their transmission / gear oil. Please post impressions, changing interval, and number of track days on the oil.

 

OEM, because you don't want to give Porsche a reason to deny warranty when the gearbox blows.

I change once a year

 

Seems like the right move given the transmission issues.

 

OEM is PTX though, right?

 

I don't know, I had my shop purchase from dealer and do the change. I hate the smell of tranny fluid

 

I tried to get the factory lube from my two local dealers. Neither stock it but they would order a 20 liter container for me.

 

Sun coast sells the OEM ptx fluid by the liter.

 

What is the difference between Mobil Delvac 75w-90 and Mobil PTX 75w-90? I've always used Delvac in previous cars, but have not changed the gear oil in the GT4 yet.

 

With how much track time you put on your car I would do it more often. Caymans are brutal on gear oil. They run much hotter than the rear engine cars. If it were my car I would be changing it every 8-12 weekends.

 

Every 6 track days for me.

 

PTX is what GT4 and Spyder parts lists call for and these cars have limited slip differentials.

 

8-12 weekends means 16-24 track days?
If so, that equates to one year for me.
I only do one day events...

 

I got my 3rd gear replaced, drove it home from the dealership like I stole it. Wife comes home a few hours later and says "what's burning in the garage?"

That's new tranny fluid baby!

 

I see PTX is specially formulated for Porsche:
http://www.mobil.com/english-IT/Pass...LUBE-PTX-75W90

I will switch to PTX in the future.

 

The PTX has some additives that are formulated for better synchro function. Otherwise they are the same oils. Delvac takes a bit longer to warm up, but once it's warm it's great, and about half the price of PTX. I suggest PTX for the guys who street drive the car year round because it offers good cold start shifting. If it's a track only car where you will go through a proper warm up any time you get on track, Delvac is fine. Delvac just isn't for impatient drivers...