transmission fluid

[tbanasiak]

I have a 1989 911 Carrera Cabriolet and am about to drain/fill the transmission fluid. I've read about the swepco201, redline, and Mobil 1 fluids. I would like any and all advice/recommendations on which is better to use. Thanks!

[JFP in PA]

Porsche has (for many years) used a proprietary gear oil formulation that several oil companies (the honest ones, anyway) admit they do not have a match for. Considering that the OEM fluid is a full synthetic, and doesn’t cost that much, why would you risk an expensive gearbox on what may or may not be a suitable lubricant?

[tbanasiak]

JFP.... good point! To the nearest dealership I go. Thanks.

[wvicary]

I have used Swepco201 and never noticed any improvement... stick with the factory stuff as suggested.

[pete917]

Swepco is great, but better for the early boxes. But very good stuff. G50's respond better to Synthentic stuff like Mobile1

[tbanasiak]

Swepco is great, but better for the early boxes. But very good stuff. G50's respond better to Synthentic stuff like Mobile1

I called and spoke with the dealers service tech and Mobil1 is what they recommended, so that's going to be it. Yes the swepco is for earlier tranns, not mine. Thanks for all the feedback.

[JFP in PA]

Only problem is that when I contacted Mobil 1's tech department, their email response was; "Currently, Mobil 1 does not supply a suitable gear oil for your application"............... Use the OEM stuff, which is a full synthetic...............

Edited September 12, 2010 by JFP in PA

[tbanasiak]

Well today I finally got around to changing trans fluid. Old fluid was swepco201, put in Mobil1 LS 75/90 and when pulling out to test drive I noticed an immediate improvement in shifting. After driving around for @20 minutes I gotta tell you shifting is like glass......................smooth smooth smooth. Car never ran and shifted so good. Night and day difference. Ashame I had to drive home and park in garage. Mobil1 is without a doubt the fluid to use.